CVE-2025-49812
CVSS v3
7.4
HIGH
EPSS Score
0.4 %
exploit probability
CISA KEV
No
known exploited
Exploitation
—
SSVC status
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.
Technical details
- CVSS v3 Vector
- 3.1
- Published
- 2025-07-10
- Last Modified
- 2025-11-04
Frequently asked questions
What is 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.
Is CVE-2025-49812 actively exploited?
Active exploitation of CVE-2025-49812 has not been confirmed. The EPSS score is 0.4%, indicating the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2025-49812?
CVE-2025-49812 has a CVSS v3 base score of 7.4 (HIGH severity), with vector string 3.1.
Is CVE-2025-49812 affecting your environment?
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