All vulnerabilities
CVE-2025-53521

F5 BIG-IP Stack-Based Buffer Overflow Vulnerability

F5 BIG-IPNetwork & edge
Open in ThreatlineRecord JSON
CVSS
9.8Critical
ExploitationExploited in the wildAdded to KEV 27 Mar 2026CISA KEV
Exploit odds (EPSS)2.30%Chance of exploitation activity in the next 30 days, higher than 83% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in17.5.1.3Also 17.1.3, 16.1.6.1 and 1 moreCVE List
Federal deadline30 Mar 2026Remediation due date for US federal agenciesCISA KEV
CISA required actionApply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. CISA KEV

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Timeline

  1. 15 Oct 2025, 13:55 UTCPublishedCVE List
  2. 27 Mar 2026Added to CISA KEVCISA KEV

Description

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

Text from CVE List

Affected versions 4

  • BIG-IPaffected: 17.5.0 before 17.5.1.3CVE List
  • BIG-IPaffected: 17.1.0 before 17.1.3CVE List
  • BIG-IPaffected: 16.1.0 before 16.1.6.1CVE List
  • BIG-IPaffected: 15.1.0 before 15.1.10.8CVE List

References 5