9.8 Critical Exploited

CVE-2026-94127 F5 BIG-IP APM Heap-based Buffer Overflow Vulnerability

Active exploitation observed

· CISA KEV catalogue

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.

Ransomware campaigns Not observed so far

Weakness CWE-122

Description

When a BIG-IP APM access policy and an OAuth profile are configured on a virtual server, specific malicious traffic can lead to remote code execution (RCE). This vulnerability is only present when BIG-IP APM is configured as an OAuth Authorization Server. Deployments using APM strictly as an OAuth Client / Resource Server (without OAuth authorization server profiles configured) are not affected by this vulnerability. Impact: This vulnerability allows an unauthenticated attacker to perform remote code execution. The BIG-IP system in Appliance mode is also vulnerable. This is a data plane issue; there is no control plane exposure. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Affected products and versions

Product	Affected versions	Fixed in
BIG-IP 21.1	21.1.0 → latest	No fix stated
BIG-IP 17.5	17.5.0 → latest	No fix stated
BIG-IP 17.1	17.1.0 → latest	No fix stated

References

my.f5.com my.f5.com

Timeline

Published September 22, 2026
Added to the KEV catalogue September 22, 2026
Last modified September 23, 2026

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