CVE-2025-49812

7.4 highEPSS 0.6%

High (7.4) in apache http server. EPSS 0.6% chance of exploitation in the next 30 days.

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

CVSS 3.1

7.4 high

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS: 0.6% chance of exploitation in the next 30 days; higher than 49% of CVEs (scores of 2026-10-31)
CWE: CWE-287
Published: 2025-07-10
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

apache:http_server

References

https://httpd.apache.org/security/vulnerabilities_24.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
https://lists.debian.org/debian-lts-announce/2025/08/msg00009.html

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