CVE-2026-120754

Uninitialized Heap Memory Disclosure via Truncated Chunk in HDF5 Scale-Offset Filter

Published Nov 3, 2026 CVSS 4.0 · 1.9 Low EPSS < 1% KEV · Not listed
Description
HDF5 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.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared The Hdf Group
The Hdf Group scale-offset Filter
Vendors & Products The Hdf Group
The Hdf Group scale-offset Filter
Type Values Removed Values Added
First Time appeared Hdfgroup
Hdfgroup hdf5
CPEs cpe:2.3:a:hdfgroup:hdf5:*:*:*:*:*:*:*:*
Vendors & Products Hdfgroup
Hdfgroup hdf5
Metrics cvssV3_1

{'score': 3.3, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Metrics cvssV4_0

{'score': 1.1, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U'}

cvssV4_0

{'score': 1.9, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P'}

Type Values Removed Values Added
Description HDF5 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.
Title Uninitialized Heap Memory Disclosure via Truncated Chunk in HDF5 Scale-Offset Filter
Weaknesses CWE-908
References
Metrics cvssV4_0

{'score': 1.1, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
HDFG
Published
Updated
Nov 3, 2026, 5:58 PM
Reserved
Nov 2, 2026, 9:30 PM
Status
Analyzed
Published
Nov 3, 2026, 4:17 PM
Modified
Nov 3, 2026, 9:10 PM
Severity
Low
Public date
Nov 3, 2026, 3:24 PM