CVE-2025-49812 — Apache HTTP Server: mod_ssl TLS upgrade attack

Description (CNA)

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.

Affected (CNA)

Vendor / product	Versions
Apache Software Foundation / Apache HTTP Server	affected 0 through 2.4.63

CWE

CWE-287

References

https://httpd.apache.org/security/vulnerabilities_24.html

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.

CVE

No English description supplied.

https://lists.debian.org/debian-lts-announce/2025/08/msg00009.html
http://www.openwall.com/lists/oss-security/2025/07/09/3
http://www.openwall.com/lists/oss-security/2025/07/10/2
http://www.openwall.com/lists/oss-security/2025/07/10/9