Vulnerability Details CVE-2026-120756
HDF5 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.
Exploit prediction scoring system (EPSS) score
CVSS Severity
CVSS v3 Score 6.1
Products affected by CVE-2026-120756
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cpe:2.3:a:hdfgroup:hdf5:-
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cpe:2.3:a:hdfgroup:hdf5:1.10.0
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cpe:2.3:a:hdfgroup:hdf5:1.10.1
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cpe:2.3:a:hdfgroup:hdf5:1.10.2
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cpe:2.3:a:hdfgroup:hdf5:1.10.3
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cpe:2.3:a:hdfgroup:hdf5:1.10.4
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cpe:2.3:a:hdfgroup:hdf5:1.12.0
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cpe:2.3:a:hdfgroup:hdf5:1.12.1
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cpe:2.3:a:hdfgroup:hdf5:1.12.2
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cpe:2.3:a:hdfgroup:hdf5:1.12.2-3
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cpe:2.3:a:hdfgroup:hdf5:1.13.0
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cpe:2.3:a:hdfgroup:hdf5:1.13.1
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cpe:2.3:a:hdfgroup:hdf5:1.13.1-1
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cpe:2.3:a:hdfgroup:hdf5:1.13.2
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cpe:2.3:a:hdfgroup:hdf5:1.13.3
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cpe:2.3:a:hdfgroup:hdf5:1.14.0
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cpe:2.3:a:hdfgroup:hdf5:1.14.1
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cpe:2.3:a:hdfgroup:hdf5:1.14.1-2
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cpe:2.3:a:hdfgroup:hdf5:1.14.2
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cpe:2.3:a:hdfgroup:hdf5:1.14.3
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cpe:2.3:a:hdfgroup:hdf5:1.14.4
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cpe:2.3:a:hdfgroup:hdf5:1.14.4.1
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cpe:2.3:a:hdfgroup:hdf5:1.14.4.2
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cpe:2.3:a:hdfgroup:hdf5:1.14.4.3
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cpe:2.3:a:hdfgroup:hdf5:1.14.5
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cpe:2.3:a:hdfgroup:hdf5:1.14.6
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cpe:2.3:a:hdfgroup:hdf5:1.4.0
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cpe:2.3:a:hdfgroup:hdf5:1.4.1
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cpe:2.3:a:hdfgroup:hdf5:1.4.2
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cpe:2.3:a:hdfgroup:hdf5:1.4.3
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cpe:2.3:a:hdfgroup:hdf5:1.4.4
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cpe:2.3:a:hdfgroup:hdf5:1.4.5
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cpe:2.3:a:hdfgroup:hdf5:1.6.0
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cpe:2.3:a:hdfgroup:hdf5:1.6.1
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cpe:2.3:a:hdfgroup:hdf5:1.6.10
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cpe:2.3:a:hdfgroup:hdf5:1.6.2
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cpe:2.3:a:hdfgroup:hdf5:1.6.3
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cpe:2.3:a:hdfgroup:hdf5:1.6.4
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cpe:2.3:a:hdfgroup:hdf5:1.6.5
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cpe:2.3:a:hdfgroup:hdf5:1.6.6
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cpe:2.3:a:hdfgroup:hdf5:1.6.7
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cpe:2.3:a:hdfgroup:hdf5:1.6.8
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cpe:2.3:a:hdfgroup:hdf5:1.6.9
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cpe:2.3:a:hdfgroup:hdf5:1.8.0
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cpe:2.3:a:hdfgroup:hdf5:1.8.1
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cpe:2.3:a:hdfgroup:hdf5:1.8.10
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cpe:2.3:a:hdfgroup:hdf5:1.8.11
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cpe:2.3:a:hdfgroup:hdf5:1.8.12
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cpe:2.3:a:hdfgroup:hdf5:1.8.13
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cpe:2.3:a:hdfgroup:hdf5:1.8.14
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cpe:2.3:a:hdfgroup:hdf5:1.8.15
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cpe:2.3:a:hdfgroup:hdf5:1.8.16
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cpe:2.3:a:hdfgroup:hdf5:1.8.17
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cpe:2.3:a:hdfgroup:hdf5:1.8.18
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cpe:2.3:a:hdfgroup:hdf5:1.8.19
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cpe:2.3:a:hdfgroup:hdf5:1.8.2
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cpe:2.3:a:hdfgroup:hdf5:1.8.20
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cpe:2.3:a:hdfgroup:hdf5:1.8.3
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cpe:2.3:a:hdfgroup:hdf5:1.8.4
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cpe:2.3:a:hdfgroup:hdf5:1.8.5
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cpe:2.3:a:hdfgroup:hdf5:1.8.6
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cpe:2.3:a:hdfgroup:hdf5:1.8.7
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cpe:2.3:a:hdfgroup:hdf5:1.8.8
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cpe:2.3:a:hdfgroup:hdf5:1.8.9
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cpe:2.3:a:hdfgroup:hdf5:2.0.0
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cpe:2.3:a:hdfgroup:hdf5:2.1.0
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cpe:2.3:a:hdfgroup:hdf5:2.1.1
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cpe:2.3:a:hdfgroup:hdf5:2.2.0