CVE-2025-49812

NameCVE-2025-49812
DescriptionIn 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.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
apache2 (PTS)bullseye2.4.62-1~deb11u1vulnerable
bullseye (security)2.4.62-1~deb11u2vulnerable
bookworm, bookworm (security)2.4.62-1~deb12u2vulnerable
trixie2.4.63-1vulnerable
sid2.4.64-1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
apache2source(unstable)2.4.64-1

Notes

https://httpd.apache.org/security/vulnerabilities_24.html#CVE-2025-49812

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