HighCVECVE-2026-76418
[CVE-2026-76418] Cisco Secure Firewall ASA Software and Cisco Secure FTD Software — Cisco Secure Firewall ASA Software and Cisco Secure FTD Software Unchecked Return Value to NULL Pointer Dereference Vulnerability
CISA KEV·Source published ·1 min read
What happened?
Cisco Secure Firewall ASA Software and Cisco Secure FTD Software contains an unchecked return value to NULL pointer dereference vulnerability that could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. 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).
Key details
- Linux kernel vulnerability allows unintended modification of page-cache-backed data.
- Missing initialization of a variable during socket buffer coalescing causes the flaw.
- ESP input processing decrypts shared fragments in place due to the issue.
- Vulnerability can be chained with two other CVEs to implant PHP webshells.
Affected
- Linux Kernel with missing variable initialization in socket buffer coalescing.
Fixes and mitigations
- Apply mitigations per vendor instructions and CISA BOD 26-04 guidance.
- Follow BOD 26-04 patching guidelines for internet-exposed assets.
- Discontinue use if mitigations are unavailable for cloud services.
Summarised by SecOraLens from CISA KEV. Always read the original source before acting. How SecOraLens verifies advisories.