CVE-2025-49812

HIGH

Apache HTTP Server < 2.4.64 - HTTP Session Hijacking via TLS Upgrade Desynchronization

Title source: llm
STIX 2.1

Description

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.

References (5)

Core 5

Scores

CVSS v3 7.4
EPSS 0.0045
EPSS Percentile 63.6%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-287
Status published
Products (1)
apache/http_server < 2.4.64
Published Jul 10, 2025
Tracked Since Feb 18, 2026