CVE-2026-53702

A stack buffer overflow flaw was found in the GStreamer H.265 codec parser library (gst-plugins-bad). When parsing a buffering period SEI message, the parser uses an incorrect loop bound derived from cpb_cnt_minus1[i] (the loop index) instead of the sub-layer 0 CPB count cpb_cnt_minus1[0] from the referenced Sequence Parameter Set. A crafted H.265 video file or stream can cause the parser to write beyond the bounds of stack-allocated CPB delay arrays, resulting in a crash or potential stack memory corruption.

The upstream maintainer confirmed this flaw causes crashes from crafted H.265 files or streams. Code execution is considered unlikely on Red Hat Enterprise Linux due to standard hardening measures including ASLR and stack protectors. The fix is public in GStreamer 1.28.3 (MR !11334, commit 48c11b7b01).

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.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.