Heap Buffer Over-read via Malformed Message Size in HDF5's H5O__chunk_deserialize

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-120756
StatePUBLISHED
AssignerHDFG
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-11-03 16:17:22 UTC
Updated2026-11-03 16:30:17 UTC
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.

Risk And Classification

Primary CVSS: v4.0 1.9 LOW from 0253b833-3e77-4dfe-9d57-17db1a2f0a74

CVSS: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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Problem Types: CWE-125 | CWE-125 CWE-125 Out-of-bounds read

VersionSourceTypeScoreSeverityVector
4.00253b833-3e77-4dfe-9d57-17db1a2f0a74Secondary1.9LOWCVSS: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/C...
4.0CNACVSS1.9LOWCVSS: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

CVSS v4.0 Breakdown

Attack Vector
Local
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
Passive
Confidentiality
Low
Integrity
None
Availability
Low
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS: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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA The HDF Group HDF5 affected < 2.3.0 Not specified

References

ReferenceSourceLinkTags
github.com/HDFGroup/hdf5/issues/6401 0253b833-3e77-4dfe-9d57-17db1a2f0a74 github.com
github.com/HDFGroup/hdf5/pull/6589 0253b833-3e77-4dfe-9d57-17db1a2f0a74 github.com
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