---
id: "CVE-2025-53521"
kind: "vulnerability"
aliases: ["CVE-2025-53521"]
title: "f5 big-ip access policy manager: When a BIG-IP APM access policy is configured on a virtual server, specific malicious traffic can lead to Remote\u2026"
severity: "critical"
cvss: 9.8
epss: null
exploited: true
status: "open"
category: "infrastructure"
products: [{"name": "F5 BIG-IP", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "f5 big-ip access policy manager", "fixed": ["15.1.10.8"], "affected": ">= 15.1.0, < 15.1.10.8", "ecosystem": "vendor"}, {"name": "f5 big-ip access policy manager", "fixed": ["16.1.6.1"], "affected": ">= 16.1.0, < 16.1.6.1", "ecosystem": "vendor"}, {"name": "f5 big-ip access policy manager", "fixed": ["17.1.3"], "affected": ">= 17.1.0, < 17.1.3", "ecosystem": "vendor"}, {"name": "f5 big-ip access policy manager", "fixed": ["17.5.1.3"], "affected": ">= 17.5.0, < 17.5.1.3", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["big-ip-apm", "exploited", "f5-big-ip", "infrastructure"]
not_affected_if: ["no-apm-module"]
published_at: "2025-10-15T14:15:48+00:00"
first_seen_at: "2026-10-23T19:11:51+00:00"
updated_at: "2026-10-23T23:44:51+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2025-53521", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-53521", "first_seen_at": "2026-10-23T23:44:51+00:00"}]
---

# f5 big-ip access policy manager: When a BIG-IP APM access policy is configured on a virtual server, specific malicious traffic can lead to Remote…

F5 BIG-IP APM has a stack-based buffer overflow that lets a remote attacker run code on the device. CISA lists it as actively exploited in the wild.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:F5 BIG-IP affected ? fixed ?
- vendor:f5 big-ip access policy manager affected >= 15.1.0, < 15.1.10.8 fixed 15.1.10.8
- vendor:f5 big-ip access policy manager affected >= 16.1.0, < 16.1.6.1 fixed 16.1.6.1
- vendor:f5 big-ip access policy manager affected >= 17.1.0, < 17.1.3 fixed 17.1.3
- vendor:f5 big-ip access policy manager affected >= 17.5.0, < 17.5.1.3 fixed 17.5.1.3

## Fix

Apply the mitigations F5 published for this issue, or discontinue use of the product if mitigations are unavailable (per CISA required action). Exact fixed versions: unknown.

## Timeline

- 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2025-53521
- 2026-10-23T23:44:51+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2025-53521

## From the sources

F5 BIG-IP APM contains a stack-based buffer overflow vulnerability that could allow a threat actor to achieve remote code execution.

CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_