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TI-2026-84383 Aliases CVE-2026-120756GHSA-m9xj-6f2h-rx5r

Heap buffer over-read in HDF5 object header parsing

Priority LOW 10CWE-125Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
Low · None · Low
Fix status
Partial Red Hat: 1 fixed, 2 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat.

Summary

HDF5 before 2.3.0 contains a heap buffer over-read in H5O__chunk_deserialize() (CWE-125). The message size check runs before the message flags and creation index are decoded, so a message can extend past the end of the chunk image. An attacker who can get a user or application to open a crafted HDF5 file can cause a denial of service or limited disclosure of process memory. The references include an exploit link.

Written with Claude Haiku 5.5 from the sources below · 2026-11-04

Description from the CNA

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.

Why it matters now

EPSS 0.00178 7th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial HDF5 (The HDF Group): 2.3.0Red Hat: 1 advisoryRed Hat: 1 fixed, 2 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
The HDF GroupHDF5before 2.3.02.3.0Patch availableCNA
  • HDF5 VendorThe HDF Group Affected before 2.3.0 Fixed in 2.3.0 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:hdfgroup:hdf5:*:*:*:*:*:*:*:*up to 2.2.0VulnerableThe HDF Group
  • cpe:2.3:a:hdfgroup:hdf5:*:*:*:*:*:*:*:* Versions up to 2.2.0 Vulnerable ·The HDF Group

Remediation

Upgrade HDF5 to version 2.3.0. Red Hat Hardened Images is fixed by RHSA-2026:94898. Red Hat Enterprise Linux AI (RHEL AI) 3 and Red Hat OpenStack Platform 13 (Queens) are affected, and Red Hat lists their plan as none available.

Written with Claude Haiku 5.5 from the sources below · 2026-11-04

  • Fix · CNA HDF5 (The HDF Group) Fixed in 2.3.0

Red Hat 1 advisory

  • RHSA-2026:94898 Released 2026-11-04 · Red Hat rating Moderate
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images hdf5-2.2.0-0.1.5.hum1@aarch64, hdf5-2.2.0-0.1.5.hum1@s390x, hdf5-2.2.0-0.1.5.hum1@src +28

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux AI (RHEL AI) 3AffectedNo fix yet: Fix deferred
Red Hat OpenStack Platform 13 (Queens)AffectedNo fix yet: Fix deferred
Red Hat Hardened ImagesFixed RHSA-2026:94898

Timeline

  1. 2026-11-03 Threatist record created from CVE-2026-120756
  2. 2026-11-03 Alias added: GHSA-m9xj-6f2h-rx5r
  3. 2026-11-03 CVSS score added · NVD
  4. 2026-11-04 Affected versions changed · Red Hat
  5. 2026-11-04 CVSS score added · Red Hat
  6. 2026-11-04 Fix available: RHSA-2026:94898 · Red Hat
  7. 2026-11-04 Fix available: Red Hat Hardened Images · Red Hat

References

Exploit 1

Patch 1

  • TI-2025-28698 hdf5 v1.14.6 was discovered to contain a heap buffer overflow via the H5Z__filter_scaleoffset function. CVSS 3.1HIGH 8.8
  • TI-2025-28697 hdf5 v1.14.6 was discovered to contain a heap buffer overflow via the H5VM_memcpyvv function. CVSS 3.1HIGH 8.8
  • TI-2020-13412 Buffer Overflow vulnerability in function H5S_close in H5S.c in HDF5 1.10.4 allows remote… CVSS 3.1HIGH 8.8
  • TI-2021-15413 Buffer Overflow vulnerability in HDFGroup hdf5-h5dump 1.12.0 through 1.13.0 allows… CVSS 3.1HIGH 7.5
  • TI-2026-26978 HDF5: H5T__conv_struct Use After Free CVSS 3.1HIGH 7.8
  • TI-2022-09532 Heap-based buffer overflow in HDF Group libhdf5 CVSS 3.1HIGH 7.8
See all 140 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences