ALAS2023-2026-1918

References: CVE-2026-49295  CVE-2026-49337  CVE-2026-49346 
FAQs regarding Amazon Linux ALAS/CVE Severity

Issue Overview:

libde265 is an open source implementation of the h.265 video codec. Prior to version 1.0.20, a crafted H.265 bitstream can cause an out-of-bounds array write in `decoder_context::process_reference_picture_set()` (`libde265/decctx.cc:1376`). The root cause is a missing aggregate bound check on predicted short-term reference picture set entries. Individual list sizes are validated, but the combined count after predicted RPS construction can exceed the 16-entry `PocStFoll` array, writing at index 16. Version 1.0.20 patches the issue. (CVE-2026-49295)

libde265 is an open source implementation of the h.265 video codec. Prior to version 1.0.20, a crafted sequence of H.265 NAL units causes `decoder_context::read_slice_NAL()` (`libde265/decctx.cc:481`) to attach slice headers to a finished picture object
that has no active image unit, resulting in attacker-controlled unbounded heap growth. The retained headers are never freed until the picture is released, which may not happen during continuous streaming. Version 1.0.20 patches the issue. (CVE-2026-49337)

libde265 is an open source implementation of the h.265 video codec. Prior to version 1.1.0, a crafted H.265 bitstream with large SPS dimensions and 16-bit bit depth causes a signed integer overflow in `de265_image_get_buffer()` (`libde265/image.cc:128`). The overflow wraps the plane allocation size to a small value (~1 KB), but the subsequent `fill_image()` call computes the real size using `size_t`, writing ~4 GB into the undersized heap buffer. Version 1.1.0 patches the issue. (CVE-2026-49346)

Issue Correction:
Run dnf update libde265 --releasever 2023.12.20260706 or dnf update --advisory ALAS2023-2026-1918 --releasever 2023.12.20260706 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.amzn2023.0.2.aarch64
    libde265-debugsource-1.0.18-1.amzn2023.0.2.aarch64
    libde265-devel-1.0.18-1.amzn2023.0.2.aarch64
    libde265-1.0.18-1.amzn2023.0.2.aarch64

src:
    libde265-1.0.18-1.amzn2023.0.2.src

x86_64:
    libde265-debuginfo-1.0.18-1.amzn2023.0.2.x86_64
    libde265-devel-1.0.18-1.amzn2023.0.2.x86_64
    libde265-1.0.18-1.amzn2023.0.2.x86_64
    libde265-debugsource-1.0.18-1.amzn2023.0.2.x86_64