Description
libde265 is an open source implementation of the h.265 video codec. Prior to version 1.0.19, `decoder_context::decode_slice_unit_tiles` (libde265/decctx.cc:920) reads `pps.CtbAddrRStoTS[ctbAddrRS]` at line 966 where `ctbAddrRS = ctbY * ctbsWidth + ctbX` is computed from PPS-supplied `colBd[]`/`rowBd[]` arrays without validating the result against `CtbAddrRStoTS.size() == sps->PicSizeInCtbsY`. A malformed PPS that passes `set_derived_values` but encodes geometry inconsistent with the SPS produces a `ctbAddrRS` past the allocation, causing a 4-byte heap-buffer-overflow READ. Version 1.0.19 fixes the issue.
References2
Metrics
- CVSS 4.0
-
6.9
MEDIUM
Score source: CNA
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 38 · as of 14 November 2026
- CWE
- CWE-125
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.