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Big Ip Access Policy ManagerApplication · F5

CVE-2026-42937

MEDIUM · 6.5 CVSS v3.1 Published 2026-05-13
Fix available
A fix is available. Upgrade to after 17.5.1.4 or later.
See remediation →
71/100
Remediation priority · Elevated
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
Incorrect permission assignment vulnerabilities exist in BIG-IP and BIG-IQ TMOS Shell (tmsh) arp and ndp commands, and in BIG-IP iControl REST. These vulnerabilities may allow an authenticated attacker to view adjacent network information.  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

Incorrect permission assignment in BIG-IP and BIG-IQ TMOS Shell (tmsh) arp and ndp commands, and in BIG-IP iControl REST, allows authenticated attackers to view adjacent network information (ARP/NDP tables) that should be restricted.

MitigationApply F5 security updates for BIG-IP and BIG-IQ to fix permission assignments in tmsh commands and iControl REST; review user role permissions to ensure least-privilege access to network adjacency information.

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:>= 16.1.0, <= 16.1.6>= 17.1.0, <= 17.1.3.1>= 17.5.0, <= 17.5.1.4
Big Ip Advanced Firewall ManagerApplication
Affected:>= 16.1.0, <= 16.1.6>= 17.1.0, <= 17.1.3.1>= 17.5.0, <= 17.5.1.4
Big Ip Advanced Web Application FirewallApplication
Affected:>= 16.1.0, <= 16.1.6>= 17.1.0, <= 17.1.3.1>= 17.5.0, <= 17.5.1.4
Big Ip AnalyticsApplication
Affected:>= 16.1.0, <= 16.1.6>= 17.1.0, <= 17.1.3.1>= 17.5.0, <= 17.5.1.4
Big Ip Application Acceleration ManagerApplication
Affected:>= 16.1.0, <= 16.1.6>= 17.1.0, <= 17.1.3.1>= 17.5.0, <= 17.5.1.4
Big Ip Application Security ManagerApplication
Affected:>= 16.1.0, <= 16.1.6>= 17.1.0, <= 17.1.3.1>= 17.5.0, <= 17.5.1.4
Big Ip Application Visibility And ReportingApplication
Affected:>= 16.1.0, <= 16.1.6>= 17.1.0, <= 17.1.3.1>= 17.5.0, <= 17.5.1.4
Big Ip Automation ToolchainApplication
Affected:>= 16.1.0, <= 16.1.6>= 17.1.0, <= 17.1.3.1>= 17.5.0, <= 17.5.1.4

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/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. Identify installed BIG-IP version
    Run `tmsh show sys version` or check `/VERSION` file on the system
    Affected if The version falls within 16.1.0-16.1.6, 17.1.0-17.1.3.1, or 17.5.0-17.5.1.4
  2. Verify authenticated user access to tmsh arp command
    As a non-administrator user with tmsh access, run `tmsh show net arp` and check if it returns ARP table entries
    Affected if The command returns ARP table data for a user who should not have permission to view it
  3. Verify authenticated user access to tmsh ndp command
    As a non-administrator user with tmsh access, run `tmsh show net ndp` and check if it returns NDP table entries
    Affected if The command returns NDP table data for a user who should not have permission to view it
  4. Check iControl REST access to network adjacency data
    Using an authenticated but low-privilege iControl REST user session, query `/mgmt/tm/net/arp/` endpoint and verify if ARP data is returned
    Affected if The API returns ARP table information to a user lacking network administrative privileges

A system is affected if it runs a version within 16.1.0-16.1.6, 17.1.0-17.1.3.1, or 17.5.0-17.5.1.4 AND any authenticated user with restricted privileges can retrieve ARP or NDP table data via tmsh or iControl REST.

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 17.5.1.4
Interim mitigation

Apply F5 security updates for BIG-IP and BIG-IQ to fix permission assignments in tmsh commands and iControl REST; review user role permissions to ensure least-privilege access to network adjacency information.

Recommended fix Moderate confidence

Upgrade to BIG-IP 16.1.7+ or 17.1.4+ or 17.5.2+ (choose the appropriate release branch)

  1. 1. Identify the exact BIG-IP or BIG-IQ version currently installed using 'tmsh show sys version' or via the web UI under System > Software > Image List
  2. 2. Confirm the module(s) affected in your deployment (APM, AFM, ASM, Analytics, AAM, AVR, or Automation Toolchain)
  3. 3. Review F5 KB article at https://my.f5.com for the specific advisory K0000xxx related to CVE-2026-42937 for version details
  4. 4. Download the fixed version (16.1.7 or later within 16.1.x, 17.1.4 or later within 17.1.x, or 17.5.2 or later within 17.5.x) from F5 downloads
  5. 5. Plan maintenance window following F5 upgrade best practices - backup configuration with 'tmsh save sys config'
  6. 6. Upload the ISO/image to the BIG-IP device via GUI (System > Software > Image Upload) or API
  7. 7. Install the new version and reboot using F5 rolling upgrade procedure to maintain service continuity
  8. 8. Verify the fix by confirming the updated version and testing that arp/ndp command permissions are properly restricted
Caveat Review F5 release notes for the target version to check for any configuration or compatibility changes; always test in non-production first

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
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,840
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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-2026-42937 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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