Quick answers
- Is CVE-2026-120755 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-120755 being exploited in the wild.
- How severe is CVE-2026-120755?
- Informational severity, published 3 November 2026.
- Which products and versions are affected?
- Hdfgroup Hdf5 through 2.2.0.
- Is there a fix for CVE-2026-120755?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-120755 attacked?
- It is attacked over the network or with local access, in a software library.
- Am I affected by CVE-2026-120755?
- 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
An out-of-bounds read in H5Z__filter_szip() occurs when processing a truncated or corrupted szip-compressed chunk shorter than 4 bytes. The function subtracts the 4-byte header from the chunk length without verifying minimum length, causing integer wraparound and reading far past the buffer end. Only HDF5 builds with szip support (libaec or szip library) are affected; the vulnerability requires a user or application to read a malicious HDF5 file.
Affected products
- HDFGroup HDF5 through 2.2.0
Timeline
- 2026-11-03: disclosed