VulnerabilityModified

CVE-2025-49630

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.

HIGH 7.5EPSS 1.21%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.21%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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".

CVSS 3.1: 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS: 1.21% probability · 67th percentile
CISA KEV: Not listed
Weakness: CWE-617
Affected: apache/http server
Source: security@apache.org

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.