CVE-2025-49630 | Apache HTTP Server: mod_proxy_http2 denial of service

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".

Published: 2025-07-10 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-49630 is rated Moderate Risk (50.4/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.15%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-49630

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 2.67% 1.15% -1.53%
2 2026-06-10 3.55% 2.67% -0.87%
3 2026-06-05 — 3.55% —

Full EPSS history (31 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-49630

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2025-49630

OS Trackers for CVE-2025-49630

vendor priority summary link
alpine — CVE-2025-49630: 1 source package rows (apache2); 5 state rows across 5 repos (3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 5, open 0. https://security.alpinelinux.org/vuln/CVE-2025-49630
debian not yet assigned CVE-2025-49630 not yet assigned priority: Debian including 1 source packages (apache2), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2025-49630
redhat medium — https://access.redhat.com/security/cve/CVE-2025-49630
suse high — https://www.suse.com/security/cve/CVE-2025-49630/
ubuntu medium CVE-2025-49630 medium priority: Ubuntu including 1 source packages (apache2), 8 status rows across 8 suites (bionic, focal, jammy, noble, plucky, trusty, upstream, xenial): released 6, not-affected 2. https://ubuntu.com/security/CVE-2025-49630

Affected software / configurations for CVE-2025-49630

Vendor Product Version Raw CPE
apache http_server >= 2.4.26, < 2.4.64 cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*

References for CVE-2025-49630

cvelogic Threat Intelligence