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PatchSiren cyber security CVE debrief

CVE-2026-40462 F5 CVE debrief

CVE-2026-40462 is a high-severity vulnerability in F5 products, allowing authenticated attackers to view sensitive information. The vulnerability exists in iControl REST and TMOS shell (tmsh) undisclosed command. Software versions that have reached End of Technical Support (EoTS) are not evaluated. The Common Vulnerability Scoring System (CVSS) score for this vulnerability is 7.1, indicating a high severity. The vulnerability was published on May 13, 2026, and last modified on June 29, 2026.

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
2026-06-29
Advisory published
2026-05-13
Advisory updated
2026-06-29

Who should care

Security teams and administrators responsible for F5 products should be aware of this vulnerability. The vulnerability affects various F5 products, including BIG-IP Access Policy Manager, BIG-IP Advanced Firewall Manager, and others. Affected organizations should review the vendor advisory and apply necessary mitigations.

Technical summary

The vulnerability exists in iControl REST and TMOS shell (tmsh) undisclosed command, allowing authenticated attackers to view sensitive information. The vulnerability affects F5 products, including BIG-IP Access Policy Manager, BIG-IP Advanced Firewall Manager, BIG-IP Advanced Web Application Firewall, and others. The CVSS vector for this vulnerability is CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/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.

Defensive priority

High

Recommended defensive actions

  • Review and apply vendor advisory K000156581
  • Inventory and assess F5 product versions for potential vulnerability
  • Implement compensating controls to limit access to sensitive information
  • Monitor for suspicious activity related to iControl REST and TMOS shell (tmsh)
  • Consider upgrading to non-vulnerable versions of F5 products

Evidence notes

The CVE record and NVD detail provide information on the vulnerability. The vendor advisory K000156581 offers mitigation guidance. The vulnerability affects multiple F5 products, and software versions that have reached End of Technical Support (EoTS) are not evaluated.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-40462 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-40462

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

  • CVE-2026-40462 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-40462

    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.