F5 BIG-IP Stack-Based Buffer Overflow Vulnerability

[ Why it matters ]Priority signals

• Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2026-03-27
• Critical severity: CVSS 9.8

[ Description ]Official description

When a BIG-IP APM access policy is configured on a virtual server, specific malicious traffic can lead to Remote Code Execution (RCE).   Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

CISA: F5 BIG-IP APM contains a stack-based buffer overflow vulnerability that could allow a threat actor to achieve remote code execution.

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 30 Mar 2026): Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ References ]References

• my.f5.com/manage/s/article/K000156741Vendor Advisory
• www.cisa.gov/known-exploited-vulnerabilities-catalogUS Government Resource