ACTIVELY EXPLOITED
CVE-2025-53521: F5 BIG-IP Stack-Based Buffer Overflow Vulnerability
| Vendor | F5 |
|---|---|
| Product | BIG-IP |
| Actively exploited | Yes |
| Added to CISA KEV | 27 Mar 2026 |
| CISA federal deadline | 30 Mar 2026 |
| Weakness (CWE) | CWE-121 |
Required action (CISA's text)
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Description (NVD)
F5 BIG-IP APM contains a stack-based buffer overflow vulnerability that could allow a threat actor to achieve remote code execution.
SOURCES
Other F5 flaws
- CVE-2026-94127: F5 BIG-IP APM Heap-based Buffer Overflow Vulnerability
- CVE-2023-46748: F5 BIG-IP Configuration Utility SQL Injection Vulnerability
- CVE-2023-46747: F5 BIG-IP Configuration Utility Authentication Bypass Vulnerability
- CVE-2022-1388: F5 BIG-IP Missing Authentication Vulnerability
- CVE-2021-22991: F5 BIG-IP Traffic Management Microkernel Buffer Overflow
Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.