CVE-2026-34379

NameCVE-2026-34379
DescriptionOpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From 3.2.0 to before 3.2.7, 3.3.9, and 3.4.9, a misaligned memory write vulnerability exists in LossyDctDecoder_execute() in src/lib/OpenEXRCore/internal_dwa_decoder.h:749. When decoding a DWA or DWAB-compressed EXR file containing a FLOAT-type channel, the decoder performs an in-place HALF→FLOAT conversion by casting an unaligned uint8_t * row pointer to float * and writing through it. Because the row buffer may not be 4-byte aligned, this constitutes undefined behavior under the C standard and crashes immediately on architectures that enforce alignment (ARM, RISC-V, etc.). On x86 it is silently tolerated at runtime but remains exploitable via compiler optimizations that assume aligned access. This vulnerability is fixed in 3.2.7, 3.3.9, and 3.4.9.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
openexr (PTS)bullseye (security), bullseye2.5.4-2+deb11u1vulnerable
bookworm3.1.5-5vulnerable
trixie3.1.13-2vulnerable
forky, sid3.4.6+ds-4vulnerable

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
openexrsource(unstable)(unfixed)

Notes

https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-w88v-vqhq-5p24
https://github.com/AcademySoftwareFoundation/openexr/pull/2324
https://github.com/AcademySoftwareFoundation/openexr/commit/3ad9b29430f9c2599dad113e1efe619a6ec7ba67 (main)
https://github.com/AcademySoftwareFoundation/openexr/commit/d32ffe9d3727c0474b63e91556baf61ced3d89e0 (v3.4.9-rc)
https://github.com/AcademySoftwareFoundation/openexr/commit/76af7d7508819a477f2cbce808ee975da8053ce3 (v3.2.7-rc)

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