CVE-2026-120756

NameCVE-2026-120756
DescriptionHDF5 through 2.2.0 contains a heap buffer over-read vulnerability in H5O__chunk_deserialize() in src/H5Ocache.c. When decoding object header messages, the declared message size is checked against the end of the chunk image before the remainder of the message header (flags, and for version 2 object headers, the optional creation index) has been decoded. Because the message body begins after these fields, a message can start up to four bytes further into the chunk than the size check accounts for. A crafted HDF5 file can declare a message size that passes the check but extends past the end of the chunk image, causing the message’s decode callback, for example H5O__mtime_new_decode() in src/H5Omtime.c, to read beyond the heap allocation. The flaw is reachable during H5Fopen() on a crafted file. An attacker who can get a user or application to open a malicious file can cause a denial of service or limited disclosure of process memory.
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/6589
https://github.com/HDFGroup/hdf5/commit/10f1af5528168c5a71a58eba0b486e0677f3aaa3
HDF not covered by security support, see https://bugs.debian.org/1117722

Search for package or bug name: Reporting problems