CVE-2025-49812

In some mod_ssl configurations on Apache HTTP Server versions through to 2.4.63, an HTTP desynchronisation attack allows a man-in-the-middle attacker to hijack an HTTP session via a TLS upgrade.

Only configurations using "SSLEngine optional" to enable TLS upgrades are affected. Users are recommended to upgrade to version 2.4.64, which removes support for TLS upgrade.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTNIST
7.4 HIGH
NETWORK
HIGH
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
apacheCNA
---
---
CISA-ADPADP
7.4 HIGH
NETWORK
HIGH
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 28%
VendorProductVersion
apachehttp_server
𝑥
< 2.4.64
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
apache2
bullseye
vulnerable
bookworm
no-dsa
bullseye (security)
2.4.65-1~deb11u1
fixed
bookworm (security)
vulnerable
trixie
2.4.65-2
fixed
forky
2.4.65-3
fixed
sid
2.4.65-3
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
apache2
plucky
Fixed 2.4.63-1ubuntu1.1
released
noble
Fixed 2.4.58-1ubuntu8.7
released
jammy
Fixed 2.4.52-1ubuntu4.15
released
focal
Fixed 2.4.41-4ubuntu3.23+esm2
released
bionic
Fixed 2.4.29-1ubuntu4.27+esm6
released
xenial
Fixed 2.4.18-2ubuntu3.17+esm16
released
trusty
needs-triage
Common Weakness Enumeration
Vulnerability Media Exposure
References
https://httpd.apache.org/security/vulnerabilities_24.html