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PatchSiren cyber security CVE debrief

CVE-2026-42930 F5 CVE debrief

CVE-2026-42930 is a high-severity vulnerability in F5 BIG-IP systems that allows authenticated attackers with the 'Administrator' role to bypass Appliance mode restrictions. This issue affects multiple BIG-IP products and versions, including those in the 16.1, 17.1, and 17.5 branches. The vulnerability has a CVSS score of 8.5, indicating high severity. Organizations should be aware of this issue and take necessary precautions to mitigate potential risks.

Vendor
F5
Product
BIG-IP
CVSS
HIGH 8.5
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

Organizations using F5 BIG-IP systems, particularly those in Appliance mode, should be aware of this vulnerability. Administrators with the 'Administrator' role are at risk of being able to bypass restrictions, potentially leading to unauthorized access or modifications. IT teams responsible for managing BIG-IP systems should prioritize patching and mitigation efforts.

Technical summary

The vulnerability exists in various BIG-IP products, including BIG-IP Access Policy Manager, Advanced Firewall Manager, Advanced Web Application Firewall, and others. The Common Vulnerabilities and Exposures (CVE) score for this issue is 8.5, indicating a high severity level. The CVSS vector is CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. This information is based on the supplied source corpus and may not reflect the full technical details of the vulnerability.

Defensive priority

High

Recommended defensive actions

  • Apply patches or mitigations provided by F5 as soon as possible.
  • Restrict access to BIG-IP systems, especially for users with the 'Administrator' role.
  • Monitor BIG-IP system logs for suspicious activity.
  • Consider implementing additional security controls, such as multi-factor authentication.
  • Review compensating controls for exposed systems while remediation is scheduled and verified.
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented.
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The CVE record was published on 2026-05-13T16:16:49.777Z and has not been modified since then. The NVD entry is currently Analyzed. This information is based on the supplied source corpus and may not reflect the full scope of the vulnerability. Further verification is recommended to ensure accurate understanding of the issue.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-42930 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-42930

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-42930 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-42930

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.