This vulnerability in GStreamer's gst-plugins-bad package allows an out-of-bounds read of one byte on the heap during parsing of malformed H.264 video files containing MVC or SVC extension slice NAL units. The flaw arises from insufficient validation of NAL unit data length before accessing slice boundary information. An attacker can exploit this by tricking a user into opening a crafted video file, leading to a crash or minor memory disclosure. The CVSS 3.1 score is 4.4 (medium), reflecting local attack vector with user interaction and limited confidentiality impact. No official patch or remediation level is currently stated in the vendor advisory. The vulnerability affects Red Hat Enterprise Linux 10, but no specific affected versions are detailed.

Successful exploitation can cause application crashes or leak a single byte of heap memory. The confidentiality impact is low, integrity is not affected, and availability impact is limited to potential crashes. The attack requires local access with user interaction (opening a malicious file). There are no known exploits in the wild at this time.

Patch status is not yet confirmed — check the Red Hat advisory at https://access.redhat.com/security/cve/CVE-2026-12892 for current remediation guidance. Until a fix is available, avoid opening untrusted or suspicious H.264 video files containing MVC or SVC extensions. No official mitigation or workaround is currently documented by Red Hat.