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CISA Known Exploited Vulnerabilities

F5 BIG-IP APM Heap-based Buffer Overflow Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV
2026-09-22
Remediation due
2026-09-25

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.

CISA notes
For temporary mitigation to allow for proactive forensic triage, apply the vendor-provided iRule. Once completed, install the final vendor patch as soon as possible. For more information please see: https://my.f5.com/manage/s/article/K000162605 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-94127

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.

Severity

CVSS 3.1 · CNA9.8 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 4.0 · CNA9.3 CRITICAL
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
SSVC · CISA-ADP
Exploitationactive
Automatableyes
Technical impacttotal

Affected Products

VendorProductAffected versions
F5BIG-IP
21.1.0 to <Hotfix-BIGIP-21.1.0.2.0.30.22-ENG
17.5.0 to <Hotfix-BIGIP-17.5.1.9.0.160.12-ENG
17.1.0 to <Hotfix-BIGIP-17.1.3.5.0.41.14-ENG

References

1 Links

Record Details

Published
2026-09-22
Last updated
2026-09-23
Assigner (CNA)
f5
Credited to
F5

CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.