All vulnerabilities

Servers and applications

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.

Severity
High 7.4
Published
10 Jul 2025
Last changed
17 Jun 2026
Added to UpHeron
17 Oct 2026
Fixed in
2.4.64
Sources
NVD

Affected software

SoftwareAffected versions
Apache HTTP ServerServers and applications · cpe:a:apache:http_server
  • Every version before 2.4.64

References

  • NVD https://nvd.nist.gov/vuln/detail/CVE-2025-49812
  • CVE.org https://www.cve.org/CVERecord?id=CVE-2025-49812