CVE-2025-49630
published 2025-07-10CVE-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…
PriorityP342high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
1.15%
63.3th percentile
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".
Affected
7 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| apache | http_server | >= 2.4.26 < 2.4.64 | 2.4.64 |
| apache_software_foundation | apache_http_server | 2.4.26 – 2.4.63 | — |
| debian | apache2 | < apache2 2.4.65-1~deb12u1 (bookworm) | apache2 2.4.65-1~deb12u1 (bookworm) |
| msrc | azl3_httpd_2.4.62-1_on_azure_linux_3.0 | — | — |
| msrc | azl3_httpd_2.4.64-1_on_azure_linux_3.0 | — | — |
| msrc | cbl2_httpd_2.4.62-1_on_cbl_mariner_2.0 | — | — |
| msrc | cbl2_httpd_2.4.64-1_on_cbl_mariner_2.0 | — | — |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
osv7.5HIGH
vendor_debian7.5HIGH
vendor_msrc7.5HIGH
vendor_redhat7.5HIGH
vendor_ubuntu7.5HIGH
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Ubuntu
Apache HTTP Server vulnerabilities
vendor_ubuntu·2025-08-19·CVSS 7.5
CVE-2024-43204 [HIGH] Apache HTTP Server vulnerabilities
Title: Apache HTTP Server vulnerabilities
Summary: Several security issues were fixed in Apache HTTP Server.
USN-7639-1 fixed several vulnerabilities in Apache. This update
provides the corresponding update for Ubuntu 16.04 LTS, Ubuntu
18.04 LTS, Ubuntu 20.04 LTS, and addressed a regression
fix (LP: #2119395). CVE-2025-49630 and CVE-2025-53020 only
affected Ubuntu 18.04 LTS and Ubuntu 20.04 LTS.
Original advisory details:
It was discovered that the Apache HTTP Server incorrectly handled
certain Content-Type response headers. A remote attacker could
possibly use this issue to perform HTTP response splitting attacks.
(CVE-2024-42516)
xiaojunjie discovered that the Apache HTTP Server mod_proxy module
incorrectly handled certain requests. A remote attacker could
possibly use this issue to
Ubuntu
Apache HTTP Server vulnerabilities
vendor_ubuntu·2025-07-16·CVSS 7.5
CVE-2025-49812 [HIGH] Apache HTTP Server vulnerabilities
Title: Apache HTTP Server vulnerabilities
Summary: Several security issues were fixed in Apache HTTP Server.
It was discovered that the Apache HTTP Server incorrectly handled certain
Content-Type response headers. A remote attacker could possibly use this
issue to perform HTTP response splitting attacks. (CVE-2024-42516)
xiaojunjie discovered that the Apache HTTP Server mod_proxy module
incorrectly handled certain requests. A remote attacker could possibly use
this issue to send outbound proxy requests to an arbitrary URL.
(CVE-2024-43204)
John Runyon discovered that the Apache HTTP Server mod_ssl module
incorrectly escaped certain data. A remote attacker could possibly use this
issue to insert escape characters into log files. (CVE-2024-47252)
Sven Hebrok, Felix Cramer, Tim Storm, Ma
Red Hat
httpd: mod_proxy_http2: untrusted input from a client causes an assertion to fail in the Apache mod_proxy_http2 module
vendor_redhat·2025-07-14·CVSS 7.5
CVE-2025-49630 [HIGH] CWE-617 httpd: mod_proxy_http2: untrusted input from a client causes an assertion to fail in the Apache mod_proxy_http2 module
httpd: mod_proxy_http2: untrusted input from a client causes an assertion to fail in the Apache mod_proxy_http2 module
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".
An assertion failure flaw was found in Apache httpd. Untrusted clients can send inputs that trigger an assertion failure in the mod_proxy_http2 module, which likely results in an Apache HTTP server crash or denial of service (DoS).
Statement: The vulnerability only affects Appache httpd if a reverse proxy is configured for an HTTP/2 backend, with the ProxyPre
Microsoft
Apache HTTP Server: mod_proxy_http2 denial of service
vendor_msrc·2025-07-08·CVSS 7.5
CVE-2025-49630 [HIGH] CWE-617 Apache HTTP Server: mod_proxy_http2 denial of service
Apache HTTP Server: mod_proxy_http2 denial of service
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update the CVE to reflect this.
Mariner: Mariner
apache: apache
Customer Action Required: Yes
Remediation: CBL-Mariner Releases
Reference: https://learn
Debian
CVE-2025-49630: apache2 - In certain proxy configurations, a denial of service attack against Apache HTTP ...
vendor_debian·2025·CVSS 7.5
CVE-2025-49630 [HIGH] CVE-2025-49630: apache2 - In certain proxy configurations, a denial of service attack against Apache HTTP ...
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".
Scope: local
bookworm: resolved (fixed in 2.4.65-1~deb12u1)
bullseye: resolved (fixed in 2.4.65-1~deb11u1)
forky: resolved (fixed in 2.4.64-1)
sid: resolved (fixed in 2.4.64-1)
trixie: resolved (fixed in 2.4.64-1)
OSV
apache2 vulnerabilities
osv·2025-08-19·CVSS 7.5
CVE-2025-49630 [HIGH] apache2 vulnerabilities
apache2 vulnerabilities
USN-7639-1 fixed several vulnerabilities in Apache. This update
provides the corresponding update for Ubuntu 16.04 LTS, Ubuntu
18.04 LTS, Ubuntu 20.04 LTS, and addressed a regression
fix (LP: #2119395). CVE-2025-49630 and CVE-2025-53020 only
affected Ubuntu 18.04 LTS and Ubuntu 20.04 LTS.
Original advisory details:
It was discovered that the Apache HTTP Server incorrectly handled
certain Content-Type response headers. A remote attacker could
possibly use this issue to perform HTTP response splitting attacks.
(CVE-2024-42516)
xiaojunjie discovered that the Apache HTTP Server mod_proxy module
incorrectly handled certain requests. A remote attacker could
possibly use this issue to send outbound proxy requests to an
arbitrary URL. (CVE-2024-43204)
John Runyon disco
OSV
apache2 vulnerabilities
osv·2025-07-16·CVSS 7.5
CVE-2024-42516 [HIGH] apache2 vulnerabilities
apache2 vulnerabilities
It was discovered that the Apache HTTP Server incorrectly handled certain
Content-Type response headers. A remote attacker could possibly use this
issue to perform HTTP response splitting attacks. (CVE-2024-42516)
xiaojunjie discovered that the Apache HTTP Server mod_proxy module
incorrectly handled certain requests. A remote attacker could possibly use
this issue to send outbound proxy requests to an arbitrary URL.
(CVE-2024-43204)
John Runyon discovered that the Apache HTTP Server mod_ssl module
incorrectly escaped certain data. A remote attacker could possibly use this
issue to insert escape characters into log files. (CVE-2024-47252)
Sven Hebrok, Felix Cramer, Tim Storm, Maximilian Radoy, and Juraj
Somorovsky discovered that the Apache HTTP Server mod_ssl mo
OSV
CVE-2025-49630: In certain proxy configurations, a denial of service attack against Apache HTTP Server versions 2
osv·2025-07-10·CVSS 7.5
CVE-2025-49630 [HIGH] CVE-2025-49630: In certain proxy configurations, a denial of service attack against Apache HTTP Server versions 2
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".
OSV
CVE-2025-49630: In certain proxy configurations, a denial of service attack against Apache HTTP Server versions 2
osv·2025-07-10·CVSS 7.5
CVE-2025-49630 [HIGH] CVE-2025-49630: In certain proxy configurations, a denial of service attack against Apache HTTP Server versions 2
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".
GHSA
GHSA-72h2-3r97-f454: In certain proxy configurations, a denial of service attack against Apache HTTP Server versions 2
ghsa_unreviewed·2025-07-10
CVE-2025-49630 [HIGH] CWE-617 GHSA-72h2-3r97-f454: In certain proxy configurations, a denial of service attack against Apache HTTP Server versions 2
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".
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2025-07-10
Published