---
cve: "CVE-2026-19028"
severity: "MEDIUM"
cvss: 6.8
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: "2026-09-12T22:41:27+02:00"
---

# CVE-2026-19028

> 6.8 MEDIUM · 🧪 PoC

## Beschreibung

H5Z__filter_fletcher32 in H5Zfletcher32.c in HDF5 through 2.3.0 computes the data length to checksum by subtracting the 4-byte trailing checksum size from the input buffer size without checking that the buffer is at least 4 bytes, allowing a size_t underflow. This allows attackers to cause a denial of service (massively out-of-bounds read and application crash in H5_checksum_fletcher32) via a crafted HDF5 file with a Fletcher32-filtered chunk smaller than 4 bytes, triggered via H5Dread, e.g. by the h5ls or h5dump tools.

## CVSS-Vektor

```
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/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/6488>
- <https://github.com/HDFGroup/hdf5/issues/6490>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-19028) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_