Is there a public exploit for CVE-2026-120756?

No public exploit for CVE-2026-120756 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-120756?

CVE-2026-120756 scores CVSS 1.9 (v4.0), rated low.

What does CVE-2026-120756 affect?

CVE-2026-120756 affects The HDF Group HDF5.

1.9 Low

HDF5 through 2.2.0 contains a heap buffer over-read vulnerability in H5Ochunkdeserialize() in src/H5Ocache.c.

CVE-2026-120756

HDF5 through 2.2.0 contains a heap buffer over-read vulnerability in H5Ochunkdeserialize() 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 H5Omtimenewdecode() 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.

Assessment

CVSS: 1.9 (v4.0)
Severity: Low
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 3 November 2026
Last updated: 3 November 2026
Affected: The HDF Group · HDF5
Assigner: HDFG

CVSS vectorCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:P

At the source

EUVD (ENISA)

References

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