CVE-2026-43951 is an out-of-bounds read vulnerability affecting Apache HTTP Server versions 2.4.0 through 2.4.67. It involves improper memory handling in the interaction of mod_headers and mod_mime modules when multiple response languages are configured. This can lead to reading memory beyond allocated buffers, potentially exposing sensitive information. The vulnerability has a CVSS 3.1 score of 6.5 (medium severity) with network attack vector, low attack complexity, no privileges required, no user interaction, and impacts confidentiality and integrity but not availability. No official remediation or patch has been documented yet.

Successful exploitation could allow an unauthenticated remote attacker to read memory outside the intended bounds of the Apache HTTP Server process. This may lead to disclosure of sensitive information and partial integrity compromise. There is no indication of availability impact. No known exploits have been reported in the wild.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, consider limiting exposure of affected Apache HTTP Server instances and monitor vendor communications for updates.