# CVE-2026-19029: HDF5 heap buffer over-read in scale-offset filter decode

Source: https://junglewise.ai/threats/cve-2026-19029-a-heap-based-buffer-over-read-in-h5z-filter-scaleoffset-in-src  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-06. Updated: 2026-10-06  
License: CC BY 4.0 with a link back

CVE-2026-19029 · Severity: info · Published 2026-10-06

HDF5 is a data management library used to store and manage large amounts of scientific and technical data. A vulnerability in the scale-offset filter decoder allows an attacker to craft a malicious HDF5 file that triggers a heap buffer over-read, causing the application to crash and resulting in a denial of service. This affects systems processing untrusted HDF5 files.

Technologies: [HDF Group HDF5](https://junglewise.ai/threats/technologies/hdf-group-hdf5). Vendors: [HDF Group](https://junglewise.ai/threats/vendors/hdf-group).

## Quick answers

**Is CVE-2026-19029 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-19029 being exploited in the wild.

**How severe is CVE-2026-19029?** Informational severity, published 6 October 2026.

**Which products and versions are affected?** HDF Group HDF5 through 2.2.0.

**Is there a fix for CVE-2026-19029?** 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-2026-19029 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-19029?** 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

A heap-based buffer over-read exists in H5Z__filter_scaleoffset() in src/H5Zscaleoffset.c, where the decoder computes output size from attacker-controlled filter parameters (d_nelmts * p.size bytes) without validating that the compressed chunk contains sufficient data. The vulnerability is triggered when stored minimum bits equal the full precision of the datatype, allowing an attacker to read past the end of the input buffer via a crafted HDF5 file. The fix adds bounds checks to validate chunk size against the parameter header and computed output size.

## Affected products

- HDF Group HDF5 through 2.2.0

## Timeline

- 2026-10-06: disclosed

## References

- [https://github.com/HDFGroup/hdf5/pull/6718](https://github.com/HDFGroup/hdf5/pull/6718)

## Related threats

- [HDF5 heap buffer over-read in external link traversal](https://junglewise.ai/threats/cve-2026-120757-hdf5-through-2-2-0-contains-a-heap-buffer-over-read)
- [HDF5 uninitialized memory read in scaleoffset filter](https://junglewise.ai/threats/cve-2026-120754-hdf5-through-2-2-0-contains-an-uninitialized-memory-read)
- [HDF5 heap-based buffer overflow in H5VM_array_fill](https://junglewise.ai/threats/cve-2026-106547-a-heap-based-buffer-overflow-in-h5vm-array-fill-in-src-h5vm-c-in)