Apache Apache
YES - ON THE CISA KEV LIST
CVE-2021-40438
Apache HTTP Server-Side Request Forgery (SSRF)
overdue since 2021-12-15
Apache: 41 entries (2.3% of all KEV entries are from this vendor); 3 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
A crafted request uri-path can cause mod_proxy to forward the request to an origin server choosen by the remote user. This issue affects Apache HTTP Server 2.4.48 and earlier.
Required action (CISA)
Apply updates per vendor instructions.
Notes
https://nvd.nist.gov/vuln/detail/CVE-2021-40438
References
Other KEV entries for this vendor: Apache
- CVE-2016-3081 - Struts (2026-10-08)
- CVE-2026-34486 - Tomcat (2026-08-04)
- CVE-2026-34197 - ActiveMQ (2026-04-16)
- CVE-2024-38475 - HTTP Server (2025-05-01)
- CVE-2025-24813 - Tomcat (2025-04-01)
- CVE-2024-45195 - OFBiz (2025-02-04)
- CVE-2024-27348 - HugeGraph-Server (2024-09-18)
- CVE-2024-38856 - OFBiz (2024-08-27)
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