CVE-2026-76418: Cisco Secure Firewall ASA Software and Cisco Secure FTD Software Unchecked Return Value to NULL Pointer Dereference Vulnerability

Patch now

HIGH 8.6EXPLOITEDREMOTEMITIGATE

CVE-2026-76418 is a high-severity flaw (CVSS 8.6) affecting Secure Firewall ASA Software and Cisco Secure FTD Software, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A vulnerability in the Remote Access SSL VPN service of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to logic errors when secondary authentication is configured on a tunnel group. An attacker could exploit

Why this priority

High severity
Exploited in the wild (CISA KEV)
Covered by 8 security sources
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	8.6 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 53%)
CISA exploited list	Yes, fix due 2026-11-01
Weakness	CWE-690
Published	2026-10-28
Last modified	2026-10-29

Publisher (CNA): Cisco Systems, Inc. · Vendor: Cisco

Last updated 2026-10-29 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-10-28 20:18 UTCPublished CVE record published
2026-10-29Exploited Added to the CISA Known Exploited Vulnerabilities list
2026-10-29 20:17 UTCUpdated Record last modified
2026-11-01Deadline CISA due date for US federal agencies to patch

Cisco Secure Firewall ASA Software and Cisco Secure FTD Software MITIGATE

Affected: See advisory

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

CISA required action

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Fedora 46 · byobu · FIXED · 7.23-1.fc46 · FEDORA-2026-08f2b53446 · source

sudo dnf upgrade --advisory=FEDORA-2026-08f2b53446

Advisories and coverage

Official advisories

CERT-FR Advisories: Vulnérabilité dans les produits Cisco (29 octobre 2026) 2026-10-29
Canadian Cyber Centre: Cisco security advisory (AV26-1102) - Update 1 2026-10-29
HKCERT: Cisco Products Denial of Service Vulnerability 2026-10-29
INCIBE-CERT Spain: Múltiples vulnerabilidades en productos de Cisco 2026-10-29
Cisco Security Advisories: Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Remote Access SSL VPN Tunnel Denial of Service 2026-10-28

Research and news

The Hacker News: Cisco Patches Actively Exploited ASA and FTD VPN Flaw That Can Crash Firewalls 2026-10-29
CSO Online Vulnerabilities: New Cisco firewall zero-day being actively exploited 2026-10-29
Vulners Bulletins: CVE-2026-76418 Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Remote Access SSL VPN Tunnel De 2026-10-28
Vulners Bulletins: CVE-2026-76418 Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Remote Access SSL VPN Tunnel De 2026-10-28

Verify at the official source NVD · CVE Program · CISA KEV catalog · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-76418?

Secure Firewall ASA Software and Cisco Secure FTD Software: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-76418 being exploited?

Yes. CVE-2026-76418 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2026-76418 affect?

CVE-2026-76418 affects Secure Firewall ASA Software and Cisco Secure FTD Software. Severity is high (CVSS 8.6). A vulnerability in the Remote Access SSL VPN service of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the de

How urgent is CVE-2026-76418?

Priority 75/100. High severity; Exploited in the wild (CISA KEV); Covered by 8 security sources; Remotely exploitable, no login, no user action

Software pages

Cisco ASA vulnerabilities · Cisco vulnerabilities

References

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