CVSS 4.0
1.9 lowCVSS: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:PCVE-2026-120754
Low (1.9) in hdfgroup hdf5. EPSS 0.1% estimated probability of exploitation activity in the next 30 days.
On this page
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.
Severity
CVSS 3.1
3.3 lowCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N- EPSS
- 0.1% estimated probability of exploitation activity in the next 30 days; 4th percentile. Scored 2026-11-04. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: none · Automatable: no · Technical impact: partial, assessed 2026-11-03. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWE
- CWE-908 Use of Uninitialized Resource
- Published
- Modified
- Record from
- the NVD, synced
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Affected
Versions
From the NVD's CPE matches.
| Product | Affected |
|---|---|
| hdfgroup:hdf5 | through 2.2.0 |
Linux distributions
| Distribution | Release | Package | Fixed in | Advisory |
|---|---|---|---|---|
| Debian | 12, 13, 14 | hdf5 | no fix listed | DEBIAN-CVE-2026-120754 |
| Azure Linux | 3 | hdf5 | no fix listed | AZL-112658 |
From the distributions' data via OSV.dev: the Debian Security Tracker; Microsoft's Azure Linux vulnerability data, MIT. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Debian.