Quick answers
- Is CVE-2026-120758 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-120758 being exploited in the wild.
- How severe is CVE-2026-120758?
- Informational severity, published 3 November 2026.
- Which products and versions are affected?
- Hdfgroup Hdf5 through 2.2.0.
- Is there a fix for CVE-2026-120758?
- A patch was published on 2026-10-03: Fix merged in PR #6377 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-120758 attacked?
- It is attacked over the network or with local access, in a software library.
- Am I affected by CVE-2026-120758?
- Check whether you run Hdfgroup Hdf5 at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A NULL pointer dereference vulnerability exists in H5HL_unprotect() in src/H5HL.c when processing corrupted HDF5 files. When the metadata cache evicts a corrupted local heap entry, the heap->prfx or heap->dblk pointers are set to NULL; subsequent calls to H5HL_unprotect() dereference these NULL pointers when calling H5AC_unpin_entry(), causing a segmentation fault in release builds and assertion failures in debug builds. The vulnerability is triggered by opening and traversing a malicious HDF5 file without requiring authentication or special privileges.
Affected products
- HDFGroup HDF5 through 2.2.0
Timeline
- 2026-11-03: disclosed
- 2026-10-03: patched: Fix merged in PR #6377