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TI-2026-85529 Aliases CVE-2026-120499

Code injection in h5io read_hdf5 allows arbitrary code execution

Priority HIGH 72CWE-502Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-502.

Summary

h5io from 0.1.0 before 0.2.6 contains a code injection flaw in read_hdf5() (CWE-95). An attacker who supplies a crafted HDF5 file can execute arbitrary code when a user reads it, because the file can carry Python code, module names or pickled objects that h5io evaluates, imports or deserializes.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

h5io before 0.2.6 contains a code injection vulnerability in read_hdf5() that allows attackers to execute arbitrary code by supplying a crafted HDF5 file. Attackers can store Python code in a node titled timezone, which _triage_read() passes to eval() with builtins reachable, name an arbitrary module in class or custom-object nodes that _import_class() imports, or place pickled objects in pd_dataframe or pd_series nodes that pandas deserializes on read.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00423 36th percentileScored 2026-11-07
Fix Fixed h5io (h5io): 0.2.6

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
h5ioh5io0.1.0 to before 0.2.60.2.6Patch availableCNA
  • h5io Vendorh5io Affected 0.1.0 to before 0.2.6 Fixed in 0.2.6 Patch available CNA

Remediation

Upgrade h5io to version 0.2.6, which fixes this flaw.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

  • Fix · CNA h5io (h5io) Fixed in 0.2.6

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-11-05 Threatist record created from CVE-2026-120499
  2. 2026-11-05 CISA SSVC decision points changed
  3. 2026-11-05 Priority changed: MEDIUM → HIGH
  4. 2026-11-06 Affected versions changed · Red Hat
  5. 2026-11-06 CVSS score added · Red Hat

References

Patch 1

Advisory 1

Other 2

Sources

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