Home/CVE/In certain proxy configurations, a denial of service attack against Apache HTTP Server versions 2.4.26 through to 2.4.6
CVE

CVE-2025-49630

In certain proxy configurations, a denial of service attack against Apache HTTP Server versions 2.4.26 through to 2.4.6

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".

HIGH · CVSS 7.5 EPSS 0.04674
Schedule remediation
  • SSVC automatable: yes - attacks can be scripted at scale
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-617Reachable Assertion
▤

Affected Products & Versions

1
apache http server>= 2.4.26 and < 2.4.64
▣

Scoring & Timeline

7.5
HIGH · CVSS v3.1 · security@apache.org
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD10 Jul 2025 · 05:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
yes
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
⚑

Vendor Advisories

21
usnUSN-7639-2
suse-csafSUSE-SU-2025:02682-1
suse-csafSUSE-SU-2025:02683-1
suse-csafSUSE-SU-2025:02684-1
suse-csafSUSE-SU-2025:02685-1
🔗

References & Sources

4
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://httpd.apache.org/security/vulnerabilities_24.htmlVendor Advisory
http://www.openwall.com/lists/oss-security/2025/07/10/2
http://www.openwall.com/lists/oss-security/2025/07/10/7
https://lists.debian.org/debian-lts-announce/2025/08/msg00009.html
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