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F5 · BIG-IP

CVE-2025-53521

F5 BIG-IP Stack-Based Buffer Overflow Vulnerability

CISA KEV record

CISA date added
2026-03-27
CISA due date
2026-03-30
Known ransomware use
Unknown

NVD risk context

9.3 CRITICAL

CVSS is a technical severity score. CISA’s KEV status remains the evidence that this vulnerability is known to be exploited.

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Attack vector
Network
The vulnerable service can be reached remotely over a network.
Attack complexity
Low
Exploitation does not require unusual conditions beyond normal attacker control.
Attack requirements
None
No additional attack condition is required.
Privileges required
None
The attacker does not need an existing account or privileges.
User interaction
None
No action by another user is required.

Description

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

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.

NVD reference index

Vendor and remediation references

NVD has tagged these sources as vendor advisories, patches, mitigations, or release notes.

Other NVD references (1)

MITRE CWE context

CWE classification

CWE-121 Stack-based Buffer Overflow

A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).

View official MITRE CWE details ↗

NVD record timing

NVD record timeline

These dates describe NVD’s record, not CISA’s KEV addition or remediation due date.

NVD published
Oct 15, 2025, 02:15 PM UTC
When NVD first published this CVE record.
NVD last updated
Jun 17, 2026, 09:38 AM UTC
When NVD last changed its analysis or record data.
Advanced: view the technical CVSS vector

This standardized code is intended for security tools and technical analysts. The plain-language risk summary above explains its main points.

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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CISA 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