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Big Ip Access Policy ManagerApplication · F5

CVE-2026-41959

MEDIUM · 6.5 CVSS v3.1 Published 2026-05-13
Fix available
A fix is available. Upgrade to after 17.5.1 or later.
See remediation →
67/100
Remediation priority · Elevated
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
Incorrect permission assignment vulnerabilities exist in BIG-IP and BIG-IQ TMOS Shell (tmsh) network diagnostics commands and in BIG-IP iControl REST. These vulnerabilities may allow an authenticated attacker to view the network status of destination systems.  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 incorrect permission assignment vulnerability in F5 BIG-IP and BIG-IQ TMOS Shell (tmsh) network diagnostics commands and BIG-IP iControl REST API. An authenticated attacker with standard user privileges can exploit improper permission checks to view network status information of destination systems that should be restricted to administrative users.

MitigationApply the relevant F5 security advisory and patch for BIG-IP/BIG-IQ. Review and restrict user role permissions for tmsh network diagnostics commands and iControl REST endpoints to enforce least-privilege access controls.

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
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/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 installed F5 BIG-IP version
    Run `tmsh show /sys version` or `bigpipe version` from the command line. Alternatively, check the web UI under System > Software Management > ISO Image or review /etc/osrelease.
    Affected if The version matches any of these ranges: 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 user roles with access to tmsh network diagnostics
    Run `tmsh list auth role` to view all defined roles and their command privileges. Look for roles that include `net` or `network` command permissions.
    Affected if Any role other than Administrator or Resource Administrator has permission to run tmsh network commands (such as `tmsh show /net stats` or `tmsh show /net route`).
  3. Verify standard user accounts exist and their assigned roles
    Run `tmsh list auth user` to list all local users. For each user, run `tmsh show auth user <username>` to see their assigned role.
    Affected if There are users assigned roles other than Administrator or Resource Administrator who can authenticate to the system.
  4. Check iControl REST API role permissions
    Review the BIG-IP APM or iControl REST role definitions: run `tmsh list auth role <role-name>` and inspect the `command` attribute for network-related API endpoints.
    Affected if Non-administrative roles (such as Guest, User, or Operator) have API access to network status endpoints.

You are affected if your F5 BIG-IP version is in the listed vulnerable ranges AND standard non-administrative users can access tmsh network diagnostics commands or iControl REST API network status endpoints.

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 the relevant F5 security advisory and patch for BIG-IP/BIG-IQ. Review and restrict user role permissions for tmsh network diagnostics commands and iControl REST endpoints to enforce least-privilege access controls.

Recommended fix Moderate confidence

Upgrade to 16.1.7+ (for 16.1.x), 17.1.4+ (for 17.1.x), 17.5.2+ (for 17.5.x), or 21.0.1+ (for 21.0.x)

  1. Identify the current BIG-IP or BIG-IQ version by running 'tmsh show sys version' or checking the web management console.
  2. Determine which affected version branch is in use (16.1.x, 17.1.x, 17.5.x, or 21.0.x).
  3. For 16.1.x installations: Upgrade to version 16.1.7 or later.
  4. For 17.1.x installations: Upgrade to version 17.1.4 or later.
  5. For 17.5.x installations: Upgrade to version 17.5.2 or later.
  6. For 21.0.x installations: Upgrade to version 21.0.1 or later.
  7. After upgrade, verify the fix by confirming the version via 'tmsh show sys version'.
  8. Test that network diagnostics commands now enforce proper permission controls as expected.
Caveat Major version upgrades may introduce configuration changes; review F5 release notes before upgrading

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
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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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-2026-41959 in production — separate from our analysis above.

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