Exploited vulnerability · CISA KEV

Is CVE-2020-5902 exploited? Yes: in CISA KEV since 3 Nov 2021

Gociux · F5 BIG-IP · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2020-5902, F5 BIG-IP Traffic Management User Interface (TMUI) Remote Code Execution Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 3 Nov 2021, 490 days after it was published. It is known to be used in ransomware campaigns. It affects F5 BIG-IP, an internet-facing product of the kind attackers use for initial access. If you run it, CISA's required action is: Apply updates per vendor instructions.

What it is

F5 BIG-IP Traffic Management User Interface (TMUI) contains a remote code execution vulnerability in undisclosed pages.

What to do

1. Check whether you run it. Look for BIG-IP in your asset inventory, including appliances and cloud images. Stack check lists every exploited F5 CVE at once.
2. Apply the fix. Apply updates per vendor instructions.
3. If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 1 Jul 2020.
4. Get told next time. Email alerts when CISA adds a CVE for F5.

Other exploited CVEs in BIG-IP

• CVE-2025-53521: F5 BIG-IP Stack-Based Buffer Overflow Vulnerability (27 Mar 2026)
• CVE-2022-1388: F5 BIG-IP Missing Authentication Vulnerability (10 May 2022)

References

• nvd.nist.gov/vuln/detail/CVE-2020-5902

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in November 2021 · F5 scorecard · act-now radar.