CVE-2025-53521—F5 BIG-IP Stack-Based Buffer Overflow Vulnerability

Vulnerability Name

F5 BIG-IP Stack-Based Buffer Overflow Vulnerability

Description

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

Known To Be Used in Ransomware Campaigns?

Ransomware Status:

Unknown

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.

Additional Notes

• Please adhere to F5’s guidelines to assess exposure and mitigate risks. Check for signs of potential compromise on all internet accessible F5 products affected by this vulnerability. For more information please see: https://my.f5.com/manage/s/article/K000156741
• https://my.f5.com/manage/s/article/K000160486
• https://my.f5.com/manage/s/article/K11438344
• https://nvd.nist.gov/vuln/detail/CVE-2025-53521

Related News Articles

• Over 14,000 F5 BIG-IP APM instances still exposed to RCE attacksApril 2, 2026
• Hackers exploiting critical F5 BIG-IP flaw in attacks, patch nowMarch 30, 2026
• Attackers are exploiting RCE vulnerability in BIG-IP APM systems (CVE-2025-53521)March 28, 2026
• CISA Adds CVE-2025-53521 to KEV After Active F5 BIG-IP APM ExploitationMarch 28, 2026

Related Weaknesses

• CWE-121