HIGH

CVE-2025-49630

Apache HTTP Server: mod_proxy_http2 denial of service

CVSS v3

7.5

HIGH

EPSS Score

1.4 %

exploit probability, as of 2026-10-18

CISA KEV

known exploited

Exploitation

none

SSVC status

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Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

apacheBitnamifrom 2.4.26 · fixed in 2.4.64
httpdAlmaLinux:8all versions · fixed in 2.4.37-65.module_el8.10.0+4044+ea5f78b1.5and 6 other packages
mod_http2AlmaLinux:10all versions · fixed in 2.0.29-2.el10_0.1
mod_http2AlmaLinux:9all versions · fixed in 2.0.26-4.el9_6.1
mod_http2AlmaLinux:8all versions · fixed in 1.15.7-10.module_el8.10.0+4044+ea5f78b1.4
mod_mdAlmaLinux:8all versions · fixed in 1:2.0.8-8.module_el8.6.0+3031+fb177b09
mod_sslAlmaLinux:8all versions · fixed in 1:2.4.37-65.module_el8.10.0+4044+ea5f78b1.5and 1 other package

Vendor advisories

CVE-2025-49630 Red Hat Product Security462 products fixed
httpd: mod_proxy_http2: untrusted input from a client causes an assertion to fail in the Apache mod_proxy_http2 module
RHSA-2025:15727 Red Hat Product Security13 products fixed
Red Hat Security Advisory: mod_http2 security update
RHSA-2025:15726 Red Hat Product Security13 products fixed
Red Hat Security Advisory: mod_http2 security update
RHSA-2025:15725 Red Hat Product Security13 products fixed
Red Hat Security Advisory: mod_http2 security update
RHSA-2025:15698 Red Hat Product Security135 products fixed
Red Hat Security Advisory: httpd:2.4 security update
RHSA-2025:15684 Red Hat Product Security50 products fixed
Red Hat Security Advisory: httpd:2.4 security update

7 more advisories

Full record on NVD

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".

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: 2025-07-10
Last Modified: 2025-11-04

Frequently asked questions

What is CVE-2025-49630?

Is CVE-2025-49630 actively exploited?

Active exploitation of CVE-2025-49630 has not been confirmed. Its EPSS score was 1.4% on 2026-10-18, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2025-49630?

CVE-2025-49630 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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