CVE-2021-40438 — Apache HTTP Server-Side Request Forgery (SSRF)

CVE-2021-40438

CRITICAL · CVSS 9 ⚠ KEV — EXPLOITED

EPSS exploitation probability: 100%

⚠ Listed in the CISA Known Exploited Vulnerabilities catalog — actively exploited.

Published 2021-12-01 · Last modified 2026-08-01T05:16:54.497

Summary

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.

Affected products

Apache — Apache

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References

NVD entry
CVE.org record

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.