Security readout for executives and security teams
Plain-English summary
A malicious HDF5 file can crash or potentially compromise systems that process it with the h5dump utility in HDF5 1.14.1-2 and earlier. The risk is highest where staff, pipelines, or researchers inspect externally supplied HDF5 data files.
Executive priority
Treat as high priority for environments that exchange or inspect HDF5 datasets. Business urgency depends on whether untrusted files reach h5dump; isolated internal-only use lowers immediate risk.
Technical view
The issue is a heap use-after-free in h5dump. A freed object is later referenced during a memmove call from H5T__conv_struct after allocation in H5D__typeinfo_init_phase3 and release in H5D__typeinfo_term. The CVSS 3.1 score is 7.8 with local attack vector and required user interaction.
Likely exposure
Organizations using HDFGroup hdf5 versions 1.14.1-2 or earlier, especially where h5dump processes HDF5 files from partners, customers, research datasets, or uploads.
Exploitation context
The bundle does not show active exploitation, and KEV is false. Exploitation requires a malicious .h5 file to be supplied and processed by h5dump. The CVSS vector indicates no privileges are required, but user interaction is required.
Researcher notes
Evidence names CWE-416 and CWE-825 and identifies the allocation, free, and later memmove reference path. The provided bundle does not include exploit proof, patch commit details, or downstream package status beyond the listed advisory references.
Mitigation direction
- Inventory HDF5 and h5dump versions across workstations, servers, containers, and pipelines.
- Avoid processing untrusted HDF5 files with vulnerable h5dump versions.
- Check HDFGroup and distribution advisories for fixed packages or vendor-specific guidance.
- Isolate file-inspection workflows using sandboxing or least-privilege execution.
- Prioritize upgrades when a vendor-supported fixed release is available.
Validation and detection
- Confirm whether installed HDF5 versions are 1.14.1-2 or earlier.
- Identify automated jobs or user workflows that run h5dump on external files.
- Review SBOMs and container images for bundled HDF5 utilities.
- Check vendor advisories for your operating system package status.
- Verify compensating controls around untrusted scientific or data-exchange files.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-416: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-825: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-34734 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H1.85.9GitHub_MCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H1.85.9redhat-SADPVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- ADP timelineredhat-SADP
Made public.
- CVE publishedCVE Program
The CVE record was published.
- ADP timelineredhat-SADP
Reported to Red Hat.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2026-04-09T20:01:51.970Z: Reported to Red Hat.
- 2026-04-09T19:01:21.794Z: Made public.
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/HDFGroup/hdf5/security/advisories/GHSA-w7v2-9cmr-pwwjCVE reference, GitHub_M · x_refsource_CONFIRM
- https://access.redhat.com/security/cve/CVE-2026-34734CVE reference, redhat-SADP · vdb-entry, x_refsource_REDHAT
- RHBZ#2457034CVE reference, redhat-SADP · issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34734.jsonCVE reference, redhat-SADP · x_sadp-csaf-vex
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Use After Free
Use After Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Expired Pointer Dereference
Expired Pointer Dereference represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.