# CVE-2025-53521

## Summary

- **CVE ID:** CVE-2025-53521
- **Severity:** HIGH
- **CVSS Score:** 9.8 (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)
- **CWE:** CWE-770, CWE-121
- **Published:** Oct 15, 2025
- **Last Modified:** Mar 31, 2026

## Description

When a BIG-IP APM Access Policy is configured on a virtual server, undisclosed traffic can cause TMM to terminate.  

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

## Affected Products

- F5 — BIG-IP (17.5.0)
- F5 — BIG-IP (17.1.0)
- F5 — BIG-IP (16.1.0)
- F5 — BIG-IP (15.1.0)

## References

- [CNA](https://my.f5.com/manage/s/article/K000156741)
- [CISA-ADP](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-53521)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 2.21%
- **EPSS Percentile:** 81.6

## Known Exploited Vulnerabilities (KEV)

- **Date Added:** Mar 27, 2026
- **Due Date:** Mar 30, 2026

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._