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CVE-2025-53521

CRITICAL KEV CISA Exploitation: ACTIVE
9.8
CVSS 3.1
Description
When a BIG-IP APM access policy is configured on a virtual server, specific malicious traffic can lead to Remote Code Execution (RCE).   Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Metadata

CVE ID
CVE-2025-53521
State
PUBLISHED
Assigner
f5
Reserved
2025-10-03 23:04 UTC
Published
2025-10-15 13:55 UTC
Last updated
2026-03-31 16:04 UTC
Primary CWE
CWE-121
CWE-121 Stack-based Buffer Overflow
Vendor / Product
F5 / BIG-IP
Sources
cve.org  ·  NVD

Severity & Metrics

9.8 CRITICAL CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
SSVC — CISA Coordinator
Exploitation
ACTIVE
Automatable
yes
Tech. Impact
total
CISA Known Exploited Vulnerability
Vulnerability name
F5 BIG-IP Stack-Based Buffer Overflow Vulnerability
Vendor
F5
Product
BIG-IP
Added to KEV
2026-03-27
Due date
2026-03-30
Ransomware
Not known
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.
CISA description
F5 BIG-IP APM contains a stack-based buffer overflow vulnerability that could allow a threat actor to achieve remote code execution.
Affected products (1)
VendorProductPlatformVersions
F5 BIG-IP — 17.5.0 < 17.5.1.3, 17.1.0 < 17.1.3, 16.1.0 < 16.1.6.1, 15.1.0 < 15.1.10.8
Weakness (CWE)
CWESourceDescription
CWE-121 cna CWE-121 Stack-based Buffer Overflow
CVSS scores (2)
ScoreSeverityVersionSourceVector
9.8 CRITICAL 3.1 cna CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.3 CRITICAL 4.0 cna CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
References (1)
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