CVE-2026-100229

A flaw was found in GStreamer's H.266 codec parser library (libgstcodecparsers). An out-of-bounds write vulnerability exists in the DCI parsing function, where a reserved field value is incorrectly accepted, causing the parser to write beyond the bounds of an internal structure. An attacker could exploit this by providing a specially crafted H.266 bitstream to a third-party application that uses this library API, potentially causing a crash or memory corruption. No standard GStreamer pipeline element currently invokes the affected code path.

This vulnerability is rated as Low severity because exploitation requires a third-party application to call the gst_h266_parser_parse_dci() public API with attacker-controlled H.266 DCI data, and no in-tree GStreamer element currently invokes this function. The H.266 parser was introduced in GStreamer 1.26. RHEL 7 (GStreamer 1.x), RHEL 8 (1.16.x), and RHEL 9 (1.22.x) do not contain H.266 support and are not affected.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

No mitigation is currently available that meets Red Hat Product Security's standards for usability, deployment, applicability, or stability.