# CVE-2025-53856: TMM vulnerability

> Attackers can cause a denial of service on F5 BIG-IP devices using ePVA by sending undisclosed traffic to virtual servers or NAT objects.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 Oct 2025
- **Updated:** 26 Feb 2026
- **Also known as:** GHSA-m5hq-gxg5-5f9x

## What is CVE-2025-53856?

CVE-2025-53856 is a high-severity denial of service vulnerability in F5 Big-Ip Access Policy Manager, published on 15 Oct 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

When a virtual server, network address translation (NAT) object, or secure network address translation (SNAT) object uses the embedded Packet Velocity Acceleration (ePVA) feature, undisclosed traffic can cause the Traffic Management Microkernel (TMM) to terminate.  To determine which BIG-IP platforms have an ePVA chip refer to  K12837: Overview of the ePVA feature https://my.f5.com/manage/s/article/K12837 .  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Weakness: CWE-705 (Incorrect Control Flow Scoping)

## Which versions are affected by CVE-2025-53856?

It affects 21 products.


Products: F5 Big-Ip Access Policy Manager, F5 Big-Ip Advanced Firewall Manager, F5 Big-Ip Advanced Web Application Firewall, F5 Big-Ip Analytics, F5 Big-Ip Application Acceleration Manager, F5 Big-Ip Application Security Manager, F5 Big-Ip Application Visibility and Reporting, F5 Big-Ip Automation Toolchain, F5 Big-Ip Carrier-Grade Nat, F5 Big-Ip Container Ingress Services, F5 Big-Ip Ddos Hybrid Defender, F5 Big-Ip Domain Name System, F5 Big-Ip Edge Gateway, F5 Big-Ip Fraud Protection Service, F5 Big-Ip Global Traffic Manager, F5 Big-Ip Link Controller, F5 Big-Ip Local Traffic Manager, F5 Big-Ip Policy Enforcement Manager, F5 Big-Ip Ssl Orchestrator, F5 Big-Ip Webaccelerator and 1 more.

## How do I fix CVE-2025-53856?

No fix has been published for CVE-2025-53856 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-53856 being exploited?

There is no known exploitation of CVE-2025-53856 in the wild and no public exploit code.

## Other vulnerabilities in F5 Big-Ip Access Policy Manager

- [CVE-2023-46747](https://insights.sbomify.com/CVE-2023-46747/): F5 BIG-IP Configuration Utility Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2022-1388](https://insights.sbomify.com/CVE-2022-1388/): F5 BIG-IP Missing Authentication (critical 9.8, exploited in the wild)
- [CVE-2021-22986](https://insights.sbomify.com/CVE-2021-22986/): F5 BIG-IP and BIG-IQ Centralized Management iControl REST Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2021-22991](https://insights.sbomify.com/CVE-2021-22991/): F5 BIG-IP Traffic Management Microkernel Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2020-5902](https://insights.sbomify.com/CVE-2020-5902/): F5 BIG-IP Traffic Management User Interface (TMUI) Remote Code Execution (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-53856 and fix it if it is affected.

What it is: CVE-2025-53856 is a high-severity denial of service vulnerability in F5 Big-Ip Access Policy Manager, published on 15 Oct 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-53856 in the wild and no public exploit code.

Affected product: F5 Big-Ip Access Policy Manager. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-53856/ (Markdown: https://insights.sbomify.com/CVE-2025-53856/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-53856
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-53856
- OSV: https://osv.dev/vulnerability/CVE-2025-53856

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From sbomify Insights: https://insights.sbomify.com/CVE-2025-53856/
Summaries are generated and may contain mistakes; the official description above is the record.