libde265 is an open source implementation of the h.265 video codec. Versions prior to 1.0.19 have a heap buffer overflow (out-of-bounds READ) exists in `decoder_context::decode_slice_unit_WPP()` in `libde265/decctx.cc`. When decoding a WPP (Wavefront Parallel Processing) HEVC slice, `ctbAddrRS` is computed as `ctbRow * ctbsWidth` inside the entry-point loop. If the PPS/SPS headers are crafted so that this value exceeds `pps.CtbAddrRStoTS.size()`, the subsequent array access `pps.CtbAddrRStoTS[ctbAddrRS]` reads past the end of the allocated vector, triggering a heap-buffer-overflow confirmed by AddressSanitizer. Version 1.0.19 patches the issue.
https://github.com/strukturag/libde265/security/advisories/GHSA-wg9q-ppqw-6q38
Published: 2026-07-21
Updated: 2026-07-23
Base Score: 6.8
Vector: CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:P
Severity: Medium
Base Score: 7.8
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Severity: High
Base Score: 6.9
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
Severity: Medium
EPSS: 0.00037