---
cve: "CVE-2026-19027"
severity: "MEDIUM"
cvss: 6.9
epss: "13%"
vendor: "The HDF Group"
kev: false
exploited: false
published: "2026-08-06 00:16:53"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-10T11:43:53+02:00"
---

# CVE-2026-19027

> 6.9 MEDIUM · 🧪 PoC

## Beschreibung

The H5Z__nbit_decompress_one_byte, H5Z__nbit_decompress_one_nooptype, and H5Z__nbit_decompress_one_atomic functions in H5Znbit.c in HDF5 through 2.3.0 advance a read index into the compressed chunk buffer without bounding it against the buffer's actual size. This allows attackers to cause an out-of-bounds heap read, and in constrained cases disclosure of adjacent heap memory into decompressed dataset values, via a crafted HDF5 file whose N-Bit filter parameters describe more decompressed data than the stored compressed chunk actually contains, triggered via H5Dread, e.g. by the h5ls or h5repack tools.

## CVSS-Vektor

```
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Lokal | good |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |

## Referenzen

- <https://github.com/HDFGroup/hdf5/pull/6497>
- <https://github.com/HDFGroup/hdf5/issues/6489>
- <https://github.com/HDFGroup/hdf5/issues/6492>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-19027) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_