ALAS2023-2026-1974

References: CVE-2026-45382  CVE-2026-45383  CVE-2026-54240  CVE-2026-54241 
FAQs regarding Amazon Linux ALAS/CVE Severity

Issue Overview:

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. (CVE-2026-45382)

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. (CVE-2026-45383)

Pixel accessor signed integer overflow causes heap OOB read/write (CVE-2026-54240)

SAO sequential filter heap buffer overflow via signed integer overflow (CVE-2026-54241)

Issue Correction:
Run dnf update libde265 --releasever 2023.12.20260720 or dnf update --advisory ALAS2023-2026-1974 --releasever 2023.12.20260720 to update your system.
More information on how to update your system can be found on this page: Amazon Linux 2023 documentation

New Packages:

aarch64:
    libde265-debuginfo-1.0.18-1.amzn2023.0.3.aarch64
    libde265-1.0.18-1.amzn2023.0.3.aarch64
    libde265-debugsource-1.0.18-1.amzn2023.0.3.aarch64
    libde265-devel-1.0.18-1.amzn2023.0.3.aarch64

src:
    libde265-1.0.18-1.amzn2023.0.3.src

x86_64:
    libde265-devel-1.0.18-1.amzn2023.0.3.x86_64
    libde265-debuginfo-1.0.18-1.amzn2023.0.3.x86_64
    libde265-debugsource-1.0.18-1.amzn2023.0.3.x86_64
    libde265-1.0.18-1.amzn2023.0.3.x86_64