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Big Ip Access Policy ManagerApplication · F5

CVE-2026-42406

HIGH · 8.7 CVSS v3.1 Published 2026-05-13
Fix available
A fix is available. Upgrade to after 17.5.1 or later.
See remediation →
93/100
Remediation priority · Urgent
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A vulnerability exists in BIG-IP and BIG-IQ systems where a highly privileged, authenticated attacker with at least the Certificate Manager role can modify configuration objects that allow running arbitrary commands.     Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

This is an authenticated command injection vulnerability in F5 BIG-IP and BIG-IQ systems. An attacker with the Certificate Manager role can modify certain configuration objects to execute arbitrary commands on the underlying system, effectively achieving code execution through the management interface.

MitigationApply available F5 patches for this vulnerability and review Certificate Manager role permissions to ensure only necessary users have this elevated privilege.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Big Ip Access Policy ManagerApplication
Affected:>= 17.1.0, <= 17.1.3>= 17.5.0, <= 17.5.1>= 16.1.0, <= 16.1.6= 21.0.0
Big Ip Advanced Firewall ManagerApplication
Affected:>= 17.1.0, <= 17.1.3>= 17.5.0, <= 17.5.1>= 16.1.0, <= 16.1.6= 21.0.0
Big Ip Advanced Web Application FirewallApplication
Affected:>= 17.1.0, <= 17.1.3>= 17.5.0, <= 17.5.1>= 16.1.0, <= 16.1.6= 21.0.0
Big Ip AnalyticsApplication
Affected:>= 17.1.0, <= 17.1.3>= 17.5.0, <= 17.5.1>= 16.1.0, <= 16.1.6= 21.0.0
Big Ip Application Acceleration ManagerApplication
Affected:>= 17.1.0, <= 17.1.3>= 17.5.0, <= 17.5.1>= 16.1.0, <= 16.1.6= 21.0.0
Big Ip Application Security ManagerApplication
Affected:>= 17.1.0, <= 17.1.3>= 17.5.0, <= 17.5.1>= 16.1.0, <= 16.1.6= 21.0.0
Big Ip Application Visibility And ReportingApplication
Affected:>= 17.1.0, <= 17.1.3>= 17.5.0, <= 17.5.1>= 16.1.0, <= 16.1.6= 21.0.0
Big Ip Automation ToolchainApplication
Affected:>= 17.1.0, <= 17.1.3>= 17.5.0, <= 17.5.1>= 16.1.0, <= 16.1.6= 21.0.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check the F5 BIG-IP software version
    Run `tmsh show sys version` or view the System > Software Management > ISO Image page in the management console
    Affected if The version falls within 17.1.0-17.1.3, 17.5.0-17.5.1, 16.1.0-16.1.6, or exactly 21.0.0
  2. Identify users with Certificate Manager role
    Run `tmsh list auth user` and look for entries containing 'certificate-manager' in the role attribute, or check User > Certificate Manager in the GUI
    Affected if Any user account has the Certificate Manager role assigned
  3. Review recent audit logs for command execution
    Check System > Logs > Audit or run `tmsh show /audit` for entries showing unexpected command execution, especially from users with Certificate Manager role
    Affected if Audit logs show arbitrary shell commands executed by a Certificate Manager role user
  4. Inspect custom Certificate Manager configuration objects
    Run `tmsh list /cm certmanager` and review any custom certificate-related configuration objects for suspicious command injection patterns in fields that accept system commands
    Affected if Custom configuration objects contain shell metacharacters or unexpected command sequences

You are affected if your BIG-IP version is in the vulnerable range AND any user account has the Certificate Manager role assigned, allowing potential command injection through certificate-related configuration objects.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 17.5.1
Interim mitigation

Apply available F5 patches for this vulnerability and review Certificate Manager role permissions to ensure only necessary users have this elevated privilege.

Recommended fix Moderate confidence

Upgrade to the fixed version specified in F5 advisory for your respective version branch (17.1.x, 17.5.x, 16.1.x, or 21.0.x) - check my.f5.com for exact version numbers

  1. Check the F5 support portal (my.f5.com) for the specific hotfix or maintenance version that addresses CVE-2026-42406
  2. Review the F5 advisory for the specific fixed version applicable to your BIG-IP module and version branch
  3. Plan maintenance window for upgrade - this is a high-privilege vulnerability that allows arbitrary command execution
  4. Backup current BIG-IP configuration before applying any update
  5. Apply the recommended hotfix or upgrade to the fixed version for your respective branch (17.1.x, 17.5.x, 16.1.x, or 21.0.x)
  6. After upgrade, verify that the Certificate Manager role permissions have been properly scoped to prevent unauthorized command execution
Caveat Review F5 release notes for any compatibility concerns or behavioral changes between your current and target version

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Big Ip Access Policy Manager Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-42406 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data