F5 BIG-IP Traffic Management Microkernel
YES - ON THE CISA KEV LIST
CVE-2021-22991
F5 BIG-IP Traffic Management Microkernel Buffer Overflow
overdue since 2022-02-01
F5: 8 entries (0.4% of all KEV entries are from this vendor); 2 added in 2026.
BOD 26-04 note: this is the date printed in the CISA catalog. A federal agency's actual deadline is set by its SSVC tier - Act (3 days), Attend (14 days), Track (60 days), or the next scheduled upgrade - counted from the KEV listing date or the date the vulnerability is identified in its environment, whichever comes first. Use the tier helper on each CVE page for your own window.
Your BOD 26-04 window (SSVC tier helper)
Your remediation window ends:
Description
The Traffic Management Microkernel of BIG-IP ASM Risk Engine has a buffer overflow vulnerability, leading to a bypassing of URL-based access controls.
Required action (CISA)
Apply updates per vendor instructions.
Notes
https://nvd.nist.gov/vuln/detail/CVE-2021-22991
References
Other KEV entries for this vendor: F5
- CVE-2026-94127 - BIG-IP APM (2026-09-22)
- CVE-2025-53521 - BIG-IP (2026-03-27)
- CVE-2023-46748 - BIG-IP Configuration Utility (2023-10-31)
- CVE-2023-46747 - BIG-IP Configuration Utility (2023-10-31)
- CVE-2022-1388 - BIG-IP (2022-05-10)
- CVE-2020-5902 - BIG-IP (2021-11-03)
- CVE-2021-22986 - BIG-IP and BIG-IQ Centralized Management (2021-11-03)
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