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13 VPN and Edge Security Vulnerabilities to Prioritize in 2026

Internet-facing VPN gateways, firewalls, and remote-access appliances remain some of the most important systems in an organization’s security architecture.

These systems sit at the boundary between the public internet and trusted internal resources. They authenticate remote users, enforce access policies, terminate encrypted sessions, and may provide privileged connectivity into sensitive networks. When attackers compromise an edge device, they can sometimes move from internet scanning to an internal foothold much faster than they could through a conventional endpoint.

This is also why vulnerabilities affecting remote-access infrastructure frequently appear in ransomware and intrusion investigations. For a broader look at how exposed services, stolen credentials, and vulnerable infrastructure contribute to compromise, see Cybersecurity Time’s Ransomware Initial Access in 2026.

Patch prioritization should therefore go beyond CVSS scores. Security teams should consider known exploitation, internet exposure, authentication requirements, privilege impact, exploit maturity, business criticality, and whether the product remains supported.

The CISA Known Exploited Vulnerabilities Catalog is particularly useful because CISA describes KEV as an authoritative source for vulnerabilities known to be exploited in the wild and recommends using it as an input to vulnerability-management prioritization.

Important: Affected versions, exploitation status, and vendor remediation instructions can change. Always verify your exact product and version against the latest vendor security advisory before making production changes.

Executive Summary

The highest-priority VPN and edge vulnerabilities usually combine one or more of these characteristics:

  • confirmed exploitation in the wild;
  • CISA KEV inclusion;
  • unauthenticated remote code execution;
  • authentication bypass;
  • root or super-administrator access;
  • high-value internet exposure;
  • persistence or post-exploitation risk;
  • documented use in ransomware campaigns.

For teams deciding between exploitation evidence and severity scoring, Cybersecurity Time’s KEV vs CVSS Patch Priority guide provides useful background.

VPN vulnerabilities to patch on internet-facing remote access systems
VPN security vulnerabilities affecting Ivanti Fortinet Palo Alto Check Point and SonicWall

Table of Contents

2026 Edge Vulnerability Priority Table

CVEVendor / ProductPrimary RiskSuggested Priority
CVE-2025-22457Ivanti Connect SecureUnauthenticated RCEP1
CVE-2025-0282Ivanti Connect SecureUnauthenticated RCEP1
CVE-2023-46805Ivanti Connect SecureAuthentication bypassP1
CVE-2024-21887Ivanti Connect SecureCommand injectionP1
CVE-2024-21893Ivanti Connect SecureSSRFP1
CVE-2024-21762FortiOS / FortiProxyRemote code executionP1
CVE-2024-55591FortiOS / FortiProxyAuthentication bypass / super-adminP1
CVE-2025-24472FortiOS / FortiProxyAuthentication bypassP1
CVE-2024-3400PAN-OS GlobalProtectRoot-level command executionP1
CVE-2024-24919Check Point VPN gatewaysInformation disclosure / credential riskP1
CVE-2026-0227PAN-OS GlobalProtectDenial of serviceP2/P3
CVE-2024-38475SonicWall SMA 100Session hijacking / persistence riskP1
CVE-2024-53704SonicOS SSLVPNAuthentication bypassP1

This prioritization is a practical Cybersecurity Time assessment, not a vendor severity classification.

Why VPN Vulnerabilities Deserve Faster Remediation

A very high CVSS score does not automatically tell security teams which vulnerability attackers are most likely to exploit first.

Consider two situations.

Vulnerability A

  • CVSS 9.8
  • internal-only server
  • no known exploitation
  • segmented network
  • strong compensating controls

Vulnerability B

  • CVSS 8.5
  • internet-facing VPN appliance
  • authentication bypass
  • known exploitation
  • direct access path toward sensitive systems

In many environments, Vulnerability B deserves the faster remediation window.

CISA’s KEV model supports this threat-informed approach: vulnerabilities with demonstrated exploitation deserve special attention because attackers have already shown that the weaknesses are operationally useful.

Organizations can also follow Cybersecurity Time’s CISA KEV Update coverage to connect new KEV additions with patching decisions.

Cybersecurity Time Edge Patch Priority Model

P1 — Immediate

Prioritize immediate remediation when a vulnerability involves:

  • known exploitation;
  • CISA KEV inclusion;
  • unauthenticated remote code execution;
  • authentication bypass;
  • root or super-admin compromise;
  • credible persistence risk;
  • ransomware-associated exploitation.

P2 — High

Use P2 for important internet-facing vulnerabilities with serious security or availability consequences but weaker evidence of active malicious exploitation.

P3 — Rapid Planned Remediation

Use P3 for significant vulnerabilities where exposure exists but exploitability, attacker activity, or business impact is lower.

P4 — Routine

Use normal maintenance scheduling where exploitation likelihood is low, exposure is tightly controlled, and effective compensating controls exist.

The priority assigned here should supplement your own asset inventory, business context, threat model, and vendor guidance.

VPN vulnerabilities to patch across Ivanti Fortinet Palo Alto and SonicWall
Ivanti, Fortinet, Palo Alto Networks, and SonicWall continue to dominate urgent edge-device remediation work.

1. CVE-2025-22457 — Ivanti Connect Secure, Policy Secure and ZTA Gateways

Priority: P1 — Immediate

CVE-2025-22457 is a stack-based buffer-overflow vulnerability affecting Ivanti remote-access products.

Ivanti says affected Connect Secure versions include releases through 22.7R2.5 and states that 22.7R2.6, released in February 2025, fully patched the vulnerability. Ivanti also warns that Pulse Connect Secure 9.1x reached end of support and should be migrated. Read the official Ivanti CVE-2025-22457 security update

Why it matters

An unauthenticated remote-code-execution vulnerability on an internet-facing remote-access appliance can provide attackers with direct execution capability on a security-critical device.

  • inventory all Ivanti Connect Secure appliances;
  • verify installed releases;
  • upgrade according to current Ivanti guidance;
  • retire unsupported Pulse Connect Secure systems;
  • review exposed systems for compromise indicators;
  • inspect administrator and VPN-session activity.

If the appliance was exposed while vulnerable, treat patching and compromise assessment as separate tasks.

2. CVE-2025-0282 — Ivanti Connect Secure, Policy Secure and ZTA Gateways

Priority: P1 — Immediate

CVE-2025-0282 is another stack-based buffer-overflow vulnerability affecting Ivanti remote-access products.

CISA states that the flaw can lead to unauthenticated remote code execution, includes it in KEV, identifies known ransomware use, and recommends hunt and remediation activity before returning affected devices to service.

Ivanti’s patch documentation also confirms fixes for CVE-2025-0282 in supported releases. Review Ivanti’s security advisory and patch history

Why it matters

An organization can patch a vulnerability today without knowing whether an attacker exploited the appliance yesterday.

That distinction matters particularly for edge devices because successful exploitation can lead to persistence, credential compromise, or unauthorized access beyond the appliance itself.

  • update affected appliances;
  • perform vendor-recommended integrity checks;
  • inspect administrative accounts;
  • examine system and VPN logs;
  • investigate suspicious configuration changes;
  • rotate relevant credentials where compromise is credible.

3. CVE-2023-46805 — Ivanti Authentication Bypass

Priority: P1 — Immediate

CVE-2023-46805 affects Ivanti Connect Secure and Policy Secure and allows an attacker to bypass authentication controls and reach restricted resources.

CISA includes the vulnerability in its KEV Catalog.

The flaw became particularly dangerous because attackers could combine it with command-injection vulnerabilities such as CVE-2024-21887.

Why it matters

An authentication bypass weakens the core trust boundary of a VPN gateway.

A device designed to determine who gets inside becomes significantly more dangerous when attackers can bypass that decision.

Verify that no vulnerable Ivanti releases remain active, and investigate appliances that were internet-accessible before remediation.

4. CVE-2024-21887 — Ivanti Command Injection

Priority: P1 — Immediate

CVE-2024-21887 is a command-injection vulnerability affecting Ivanti Connect Secure and Policy Secure.

CISA notes that the vulnerability can be leveraged together with CVE-2023-46805.

Ivanti’s patch history confirms releases containing fixes for both vulnerabilities. See Ivanti’s official patch documentation

Why it matters

Security teams should evaluate vulnerability chains, not only isolated CVEs.

An attack path can progress from:

internet exposure → authentication bypass → command execution → persistence

even if separate vulnerability-management tickets exist for each weakness.

5. CVE-2024-21893 — Ivanti SSRF

Priority: P1 — Immediate

CVE-2024-21893 is a server-side request forgery vulnerability in the SAML component of affected Ivanti products.

CISA states that it can allow an unauthenticated attacker to access certain restricted resources and includes it in KEV.

Why it matters

SSRF on a perimeter appliance can allow an external attacker to cause a trusted system to interact with resources that would not normally be exposed to the attacker directly.

  • verify fixed firmware;
  • review historical exposure;
  • examine suspicious requests where logging allows;
  • follow current Ivanti compromise-assessment guidance.

6. CVE-2024-21762 — FortiOS and FortiProxy SSL-VPN

Priority: P1 — Immediate

CVE-2024-21762 affects Fortinet SSL-VPN functionality and involves an out-of-bounds write condition capable of creating serious risk on exposed systems.

For perimeter systems, the most important question is not merely the vulnerability’s score but whether a vulnerable SSL-VPN interface remains reachable from the internet.

  • identify FortiGate and FortiProxy deployments;
  • determine whether SSL-VPN is enabled;
  • verify exact firmware versions;
  • apply current Fortinet fixes;
  • minimize unnecessary internet exposure;
  • review historical authentication activity.

Use the Fortinet PSIRT portal to verify the current affected-version and remediation information before production changes.

7. CVE-2024-55591 — FortiOS and FortiProxy Authentication Bypass

Priority: P1 — Immediate

CVE-2024-55591 is a critical authentication-bypass vulnerability affecting FortiOS and FortiProxy.

Fortinet says crafted requests may allow a remote attacker to gain super-admin privileges, assigns the advisory a critical severity rating, and confirms exploitation in the wild. Read Fortinet advisory FG-IR-24-535

Why it matters

Super-administrator access to a security appliance can give an attacker significant control over:

  • administrator accounts;
  • VPN configuration;
  • firewall rules;
  • network objects;
  • security policies;
  • access to internal networks.
  • install a fixed release;
  • restrict administrative interfaces;
  • inspect administrator creation events;
  • review configuration modifications;
  • investigate unexpected SSLVPN users;
  • use Fortinet’s listed indicators of compromise.

Fortinet’s advisory contains specific logging patterns and observed attacker behavior useful during investigation.

8. CVE-2025-24472 — FortiOS and FortiProxy

Priority: P1 — Immediate

CVE-2025-24472 appears in the same Fortinet advisory family as CVE-2024-55591.

Fortinet’s current advisory covers both CVEs and confirms known exploitation for the vulnerability family.

When reviewing CVE-2024-55591, verify CVE-2025-24472 exposure in the same remediation process.

Check:

  • software branch;
  • patched release;
  • management exposure;
  • Security Fabric configuration;
  • administrator activity;
  • Fortinet indicators of compromise.

This reduces the chance of fixing one exposure while overlooking another closely related path.

9. CVE-2024-3400 — Palo Alto Networks PAN-OS GlobalProtect

Priority: P1 — Immediate

CVE-2024-3400 is one of the most important GlobalProtect vulnerabilities affecting recent PAN-OS environments.

Palo Alto Networks states that the vulnerability can allow an unauthenticated attacker to execute arbitrary code with root privileges on affected firewalls in specific GlobalProtect configurations. The vendor reports exploitation activity and recommends upgrading immediately to a fixed PAN-OS release. Read the official Palo Alto Networks CVE-2024-3400 advisory

Why it matters

Root-level control of a firewall can potentially expose:

  • routing information;
  • VPN configuration;
  • network sessions;
  • authentication pathways;
  • firewall policies;
  • trusted network relationships.

Palo Alto Networks also documented post-exploitation persistence concerns and provides additional remediation guidance for potentially compromised systems.

  • identify GlobalProtect-enabled devices;
  • install fixed PAN-OS releases;
  • investigate suspected exploitation;
  • preserve forensic information where appropriate;
  • follow vendor compromise-remediation instructions.

10. CVE-2024-24919 — Check Point VPN Information Disclosure

Priority: P1 — Immediate

CVE-2024-24919 is a stronger fit for this list than the low-severity CVE-2025-0133 included in the original article.

Check Point says CVE-2024-24919 can allow an attacker to read certain information from internet-connected gateways with remote-access VPN or Mobile Access enabled. The company observed attack attempts against remote-access environments and released a security fix. Read Check Point’s CVE-2024-24919 security update

Later Check Point research described attackers exploiting the vulnerability to obtain VPN credentials, establish legitimate VPN sessions, move laterally, deploy ShadowPad, and—in a small number of reported cases—ultimately reach ransomware deployment.

Why it matters

Information disclosure should not automatically be treated as low priority.

If leaked information helps attackers obtain usable VPN credentials, it can become part of an effective initial-access chain.

  • install Check Point’s security fix;
  • identify outdated local VPN accounts;
  • disable unused accounts;
  • eliminate password-only remote access where possible;
  • review suspicious VPN sessions;
  • strengthen authentication.

11. CVE-2026-0227 — PAN-OS GlobalProtect Denial of Service

Priority: P2/P3

CVE-2026-0227 affects PAN-OS and Prisma Access environments with an enabled GlobalProtect gateway or portal.

Palo Alto Networks says an unauthenticated attacker can cause a denial-of-service condition and that repeated attempts can force the firewall into maintenance mode.

The vendor rates the issue High severity but assigns Moderate urgency and currently reports no known malicious exploitation. Read the CVE-2026-0227 advisory

Why it matters

Availability of an edge firewall affects more than one system.

A successful denial-of-service attack could disrupt:

  • remote workers;
  • branch connectivity;
  • protected applications;
  • dependent network services;
  • perimeter availability.

However, an unexploited DoS flaw normally should not outrank an actively exploited authentication-bypass or RCE vulnerability simply because both carry high severity ratings.

12. CVE-2024-38475 — SonicWall SMA 100 Series

Priority: P1 — Immediate

CVE-2024-38475 affects SonicWall SMA 100 Series remote-access appliances.

SonicWall has associated this vulnerability with unauthorized file access and session-hijacking risk, and later urgent guidance discussed exploitation involving the OVERSTEP rootkit.

Review SonicWall’s CVE-2024-38475 PSIRT advisory

Why it matters

Session hijacking can allow an attacker to abuse an authenticated session without completing the normal login process.

Where rootkit or persistence concerns exist, remediation becomes an incident-response task rather than a conventional patching task.

  • install the latest supported SMA firmware;
  • review historical exposure;
  • investigate suspicious sessions;
  • reset authentication bindings where recommended;
  • search for persistence indicators;
  • follow SonicWall’s current recovery instructions.

13. CVE-2024-53704 — SonicWall SonicOS SSLVPN

Priority: P1 — Immediate

CVE-2024-53704 affects the SonicOS SSLVPN authentication mechanism.

An authentication-bypass weakness on an externally accessible VPN service should receive a short remediation window because it affects the security boundary responsible for deciding who can establish remote access.

Review SonicWall’s CVE-2024-53704 PSIRT advisory

  • identify affected SonicOS systems;
  • upgrade to vendor-recommended firmware;
  • inspect SSLVPN activity;
  • validate MFA configuration;
  • disable unused remote-access functionality;
  • investigate unexpected VPN sessions.

Which VPN Vulnerabilities Should You Patch First?

When remediation resources are constrained, prioritize vulnerabilities that combine:

known exploitation + internet exposure + authentication bypass/RCE + privileged impact.

A reasonable first wave would include:

Ivanti

CVE-2025-22457
CVE-2025-0282
CVE-2023-46805
CVE-2024-21887
CVE-2024-21893

Fortinet

CVE-2024-21762
CVE-2024-55591
CVE-2025-24472

Palo Alto Networks

CVE-2024-3400

Check Point

CVE-2024-24919

SonicWall

CVE-2024-38475
CVE-2024-53704

For security teams trying to formalize this approach, see Cybersecurity Time’s KEV vs CVSS Patch Priority guide.

Do Not Prioritize by CVSS Alone

CVSS is valuable for communicating technical severity, but vulnerability management should also incorporate operational context.

Ask six additional questions.

1. Is the vulnerability actively exploited?

Real attacker use significantly changes urgency.

2. Is the affected service internet-facing?

An exposed gateway presents a different risk profile from an isolated internal workload.

3. Does exploitation require authentication?

Unauthenticated vulnerabilities are typically easier for external attackers to reach.

4. What privilege could an attacker gain?

Root or super-administrator access can dramatically increase impact.

5. How important is the asset?

A perimeter firewall, identity provider, VPN gateway, or remote-management server can deserve faster remediation than a less privileged system.

6. Does the appliance still receive security updates?

Unsupported internet-facing systems create persistent exposure.

For ongoing KEV-focused remediation, Cybersecurity Time’s CISA KEV Update can be used as a companion resource.

What to Do Before Patching

Before changing a critical VPN or firewall appliance, record:

  1. appliance model;
  2. exact firmware version;
  3. enabled VPN features;
  4. management-interface exposure;
  5. HA/failover configuration;
  6. configuration backups;
  7. relevant logs;
  8. current vendor upgrade path.

If exploitation is suspected, preserve evidence before performing changes that could destroy useful forensic information.

What to Do After Patching

A successful software update is only part of the remediation process.

Verify every device

Check:

  • active node;
  • HA peer;
  • standby appliance;
  • DR infrastructure;
  • branch appliances;
  • lab devices;
  • forgotten public-facing systems.

Review administrator accounts

Look for:

  • unexpected administrator creation;
  • unexplained role changes;
  • unusual source addresses;
  • suspicious password resets;
  • new API credentials;
  • altered authentication policies.

Review VPN sessions

Investigate:

  • impossible travel;
  • unfamiliar IP addresses;
  • unusual countries;
  • disabled accounts creating sessions;
  • long-running sessions;
  • unexpected login times;
  • repeated authentication failures.

Rotate credentials where compromise is credible

Depending on the incident and vendor guidance, consider rotating:

  • administrative passwords;
  • VPN credentials;
  • service-account secrets;
  • API credentials;
  • certificates or tokens.

Hunt for persistence

For vulnerabilities that enable code execution or privileged access, use vendor-specific indicators rather than relying solely on generic malware scans.

Strengthen Authentication After Edge Remediation

Patching a VPN appliance addresses software vulnerabilities, but organizations should also reduce identity-related risk.

Cybersecurity Time’s Phishing-Resistant MFA Checklist explains how passkeys, FIDO2, and stronger authentication can reduce credential-phishing risk.

For a direct comparison between authentication methods, see Passkeys vs MFA vs SMS 2FA.

MFA is important, but it should not be misunderstood as a substitute for patching. An unauthenticated RCE vulnerability may allow attackers to bypass the normal login process altogether.

A strong edge-security strategy therefore combines:

timely patching + phishing-resistant authentication + limited exposure + log monitoring + incident response.

VPN Vulnerability Response Checklist

Asset inventory

  • Is the product deployed?
  • Which versions exist?
  • Where are the appliances located?
  • Are unsupported systems still online?

Exposure

  • Is the affected service enabled?
  • Is it reachable from the internet?
  • Is management access publicly available?

Threat intelligence

  • Is the CVE in CISA KEV?
  • Has the vendor confirmed exploitation?
  • Is public exploit material available?
  • Has ransomware activity been associated with it?

Impact

  • Can exploitation bypass authentication?
  • Can it execute code?
  • Can it provide root/admin access?
  • Can it steal sessions or credentials?
  • Can it disrupt availability?

Remediation

  • Is a patch available?
  • Does a mitigation exist?
  • Should the device be isolated?
  • Does the vendor recommend compromise hunting?
  • Is rebuilding necessary after confirmed compromise?

Frequently Asked Questions

Why are VPN vulnerabilities high priority?

VPN appliances are often internet-facing and trusted to provide access into internal environments. Compromising one can give an attacker a valuable initial foothold.

What is CISA KEV?

CISA’s Known Exploited Vulnerabilities Catalog contains vulnerabilities with evidence of exploitation in the wild and is intended to help organizations prioritize remediation. Visit the CISA KEV Catalog

Should every KEV vulnerability be patched first?

KEV is a strong urgency signal, but asset presence, internet exposure, business criticality, and compensating controls still matter.

Is CVSS enough for patch prioritization?

No. CVSS helps describe technical severity, but real-world exploitation, exposure, attacker requirements, and asset context should also influence remediation order.

Does MFA protect against VPN vulnerabilities?

It helps against credential compromise, but MFA cannot reliably stop vulnerabilities that bypass authentication or execute code directly on the VPN appliance.

Is patching enough after active exploitation?

Not always. A previously exposed appliance may require investigation for persistence, unauthorized accounts, stolen credentials, malicious sessions, or configuration changes.

Should unsupported VPN appliances remain online?

Internet-facing products that no longer receive security fixes should normally be migrated or replaced according to vendor guidance.

Final Takeaway

VPN gateways and edge-security appliances deserve some of the shortest vulnerability-remediation windows in an organization.

The strongest prioritization model is not simply:

highest CVSS score first.

A more useful model is:

known exploitation → internet exposure → authentication bypass/RCE → privilege impact → asset criticality.

For the vulnerabilities in this guide, organizations should identify affected Ivanti, Fortinet, Palo Alto Networks, Check Point, and SonicWall deployments, verify firmware against current official advisories, and remediate exposed vulnerable systems promptly.

Where exploitation may already have occurred, go further than patching.

Review privileged accounts, inspect VPN sessions, preserve evidence, hunt for persistence, strengthen authentication, and reduce unnecessary internet exposure.

A patch closes the vulnerability. A complete investigation helps determine whether an attacker used it before you did.

Primary Sources

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