CVE-2026-120754

NameCVE-2026-120754
DescriptionHDF5 through 2.2.0 contains an uninitialized memory read vulnerability in H5Z__filter_scaleoffset() in src/H5Zscaleoffset.c. The decode path validates reads against the allocated size of the chunk buffer rather than the number of bytes actually read from the file. Because H5D__chunk_lock() deliberately sizes filtered chunk buffers to the larger of the stored and unfiltered chunk sizes and fills only the stored bytes, a truncated chunk passes these bounds checks and is decompressed from the uninitialized remainder of the allocation. Unrelated heap contents are then returned to the caller as dataset data. Because the reads remain within the allocation, the issue is not detected by AddressSanitizer. An attacker who can get a user or application to read a dataset from a crafted HDF5 file can cause disclosure of process memory. This issue exists because of an incomplete fix for CVE-2026-19029.
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
hdf5 (PTS)bookworm1.10.8+repack1-1vulnerable
trixie1.14.5+repack-3vulnerable
forky2.2.0+repack-5vulnerable
sid2.2.0+repack-6vulnerable

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

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
hdf5source(unstable)(unfixed)unimportant

Notes

https://github.com/HDFGroup/hdf5/pull/6585
https://github.com/HDFGroup/hdf5/commit/cdb13c4de9c7edbbae180f384e2e610a3b3cf185
HDF not covered by security support, see https://bugs.debian.org/1117722

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