ALPINE-CVE-2026-50142

libheif is a HEIF and AVIF file format decoder and encoder. From 1.19.0 until 1.23.0, a crafted HEIF sequence accepted by heifcontextreadfrommemory() with the msf1 sequence brand can cause unbounded heap allocation. In libheif/sequences/seqboxes.cc, Boxstsz::parse() applies maxsequenceframes only to variable-size samples, so fixed-size mode accepts an attacker-controlled samplecount without a bound. In libheif/sequences/track.cc, Track::load() also adds currentsampleidx and samplesper_chunk in 32-bit arithmetic, allowing the consistency check to be bypassed by wraparound. The resulting values reach the Chunk::Chunk() allocation path, which can consume gigabytes of memory and crash or stall the process through memory exhaustion. This issue is fixed in version 1.23.0.