CVE-2025-49630

Apache HTTP Server: mod_proxy_http2 denial of service

State: Published
Severity: 7.5 High
Published: Jul 10, 2025
Updated: Nov 4, 2025
Reserved: Jun 8, 2025

Description

In certain proxy configurations, a denial of service attack against Apache HTTP Server versions 2.4.26 through to 2.4.63 can be triggered by untrusted clients causing an assertion in mod_proxy_http2.

Configurations affected are a reverse proxy is configured for an HTTP/2 backend, with ProxyPreserveHost set to "on".

Scores

CVSS	Score	Vector	Source
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	CISA-ADP

Weaknesses

CWE-617 Reachable Assertion

Affected Products

Product	Versions
Apache HTTP ServerApache Software Foundation	2.4.26 through 2.4.63Affected

References

https://httpd.apache.org/security/vulnerabilities_24.htmlvendor-advisory
https://lists.debian.org/debian-lts-announce/2025/08/msg00009.html
http://www.openwall.com/lists/oss-security/2025/07/10/2
http://www.openwall.com/lists/oss-security/2025/07/10/7

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