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PatchSiren cyber security CVE debrief

CVE-2026-42919 F5 CVE debrief

CVE-2026-42919 is a high-severity vulnerability in F5 BIG-IP systems that allows authenticated attackers with administrative access to escalate privileges. A successful exploit may allow the attacker to cross a security boundary. The vulnerability affects multiple versions of BIG-IP products, including BIG-IP Access Policy Manager, BIG-IP Advanced Firewall Manager, and others. This vulnerability is particularly concerning because it allows authenticated attackers with administrative access to escalate their privileges, potentially leading to a complete compromise of the system. The CVE record and NVD entry provide limited details about the vulnerability, but it is classified as CWE-121.

Vendor
F5
Product
BIG-IP
CVSS
HIGH 7.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-13
Original CVE updated
2026-06-18
Advisory published
2026-05-13
Advisory updated
2026-06-18

Who should care

Administrators and security teams responsible for F5 BIG-IP systems should be aware of this vulnerability and take immediate action to mitigate the risk. This vulnerability is particularly concerning because it allows authenticated attackers with administrative access to escalate their privileges, potentially leading to a complete compromise of the system. These teams should review the official advisory from F5 and assess their own deployments to determine the level of exposure.

Technical summary

The vulnerability exists in BIG-IP systems and may allow an authenticated attacker with administrative access to escalate their privileges. A successful exploit may allow the attacker to cross a security boundary. The affected products include BIG-IP Access Policy Manager, BIG-IP Advanced Firewall Manager, BIG-IP Advanced Web Application Firewall, and others. The vulnerability is classified as CWE-121. However, specific technical details about the vulnerability, such as the root cause or potential exploits, are not provided in the CVE record or NVD entry.

Defensive priority

High

Recommended defensive actions

  • Apply patches or updates provided by F5 to vulnerable BIG-IP systems
  • Restrict administrative access to BIG-IP systems
  • Monitor BIG-IP systems for suspicious activity
  • Implement compensating controls, such as Web Application Firewalls (WAFs)
  • Conduct regular vulnerability assessments and penetration testing
  • Review relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record was published on 2026-05-13T16:16:49.263Z and was last modified on 2026-06-18T13:54:35.873Z. The NVD entry is currently Analyzed. The vulnerability affects multiple versions of BIG-IP products, including BIG-IP Access Policy Manager, BIG-IP Advanced Firewall Manager, and others. However, specific version details are not provided in the CVE record or NVD entry. To verify affected scope, defenders should review the official advisory from F5 and assess their own deployments.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-05-13T16:16:49.263Z and has not been modified since then. The NVD entry is currently Analyzed.