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Big Ip Access Policy ManagerApplication · F5

CVE-2026-41956

HIGH · 7.5 CVSS v3.1 Published 2026-05-13
Fix available
A fix is available. Upgrade to after 17.5.1 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges 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
When a classification profile is configured on a UDP virtual server, undisclosed requests can cause the Traffic Management Microkernel (TMM) to terminate.  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

A denial-of-service vulnerability exists in F5 BIG-IP where a classification profile configured on a UDP virtual server can be triggered by specific undisclosed requests, causing the Traffic Management Microkernel (TMM) to terminate. This results in service disruption for traffic processed by affected virtual servers.

MitigationApply the vendor-supplied patch or update to a supported version. If immediate patching is not feasible, consider removing or disabling the classification profile from affected UDP virtual servers as a temporary workaround.

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
Big Ip Advanced Firewall ManagerApplication
Affected:>= 17.1.0, <= 17.1.3>= 17.5.0, <= 17.5.1>= 16.1.0, <= 16.1.6
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
Big Ip AnalyticsApplication
Affected:>= 17.1.0, <= 17.1.3>= 17.5.0, <= 17.5.1>= 16.1.0, <= 16.1.6
Big Ip Application Acceleration ManagerApplication
Affected:>= 17.1.0, <= 17.1.3>= 17.5.0, <= 17.5.1>= 16.1.0, <= 16.1.6
Big Ip Application Security ManagerApplication
Affected:>= 17.1.0, <= 17.1.3>= 17.5.0, <= 17.5.1>= 16.1.0, <= 16.1.6
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
Big Ip Automation ToolchainApplication
Affected:>= 17.1.0, <= 17.1.3>= 17.5.0, <= 17.5.1>= 16.1.0, <= 16.1.6

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

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

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 BIG-IP version
    Run 'tmsh show sys version' or 'tmsh list sys version' to obtain the installed software version
    Affected if The version falls within 17.1.0-17.1.3, 17.5.0-17.5.1, or 16.1.0-16.1.6
  2. Identify UDP virtual servers
    Run 'tmsh list ltm virtual' and filter for virtual servers with 'protocol udp' in their configuration
    Affected if Any virtual server is configured with UDP as the protocol
  3. Check for classification profiles on UDP virtual servers
    For each UDP virtual server, run 'tmsh list ltm virtual <virtual_name>' and look for a 'classification' profile in the profiles section
    Affected if A classification profile is attached to any UDP virtual server

You are affected if your BIG-IP runs an affected version AND has a classification profile configured on a UDP virtual server

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 vendor-supplied patch or update to a supported version. If immediate patching is not feasible, consider removing or disabling the classification profile from affected UDP virtual servers as a temporary workaround.

Recommended fix Moderate confidence

BIG-IP 17.1.4+ / 17.5.2+ / 16.1.7+ (upgrade to the latest available release in your version branch)

  1. 1. Identify all Big IP devices running affected versions (17.1.0-17.1.3, 17.5.0-17.5.1, 16.1.0-16.1.6) in your environment
  2. 2. Review F5 K13502432 on my.f5.com for the complete list of affected versions and fixed releases
  3. 3. Schedule a maintenance window for the upgrade
  4. 4. Download the appropriate Hotfix (HF) or upgrade to the fixed version for your release train
  5. 5. For BIG-IP 17.1.x: upgrade to 17.1.4 or later
  6. 6. For BIG-IP 17.5.x: upgrade to 17.5.2 or later
  7. 7. For BIG-IP 16.1.x: upgrade to 16.1.7 or later
  8. 8. After upgrade, verify TMM is running and the classification profile functions correctly
Caveat Review F5 release notes for your target version for any behavior changes; upgrading between major version branches may require configuration review

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
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,390
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,224.

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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-2026-41956 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