Quick answers
- Is CVE-2026-120754 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-120754 being exploited in the wild.
- How severe is CVE-2026-120754?
- Informational severity, published 3 November 2026.
- Which products and versions are affected?
- HDF Group HDF5 through 2.2.0.
- Is there a fix for CVE-2026-120754?
- 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-2026-120754 attacked?
- It is attacked over the network or with local access, in a software library.
- Am I affected by CVE-2026-120754?
- Check whether you run HDF Group 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
The H5Z__filter_scaleoffset() function in src/H5Zscaleoffset.c bounds-checks decoded data against the allocated buffer size rather than the number of bytes actually read from storage. Because H5D__chunk_lock() allocates buffers to MAX(stored size, unfiltered size) and fills only stored bytes, truncated chunks bypass validation and decompress uninitialized heap memory. The vulnerability requires opening a crafted HDF5 file and reading a dataset; the information disclosure results from unrelated heap contents being returned as legitimate dataset data.
Affected products
- HDF Group HDF5 through 2.2.0
Timeline
- 2026-11-03: disclosed