CVE catalog
CVE-2026-19027
The H5Z__nbit_decompress_one_byte, H5Z__nbit_decompress_one_nooptype, and H5Z__nbit_decompress_one_atomic functions in H5Znbit.c in HDF5 prior to 2.3.0 advance a read index into the compressed chunk b
- Severity
- Medium · CVSS 6.9
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.19% · Oct 25, 2026
The H5Z__nbit_decompress_one_byte, H5Z__nbit_decompress_one_nooptype, and H5Z__nbit_decompress_one_atomic functions in H5Znbit.c in HDF5 prior to 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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | hdf5 | sid | 2.2.0+repack-5 | vulnerable |
| Debian | hdf5 | forky | 2.2.0+repack-5 | vulnerable |
| Debian | hdf5 | trixie | 1.14.5+repack-3 | vulnerable |
| Debian | hdf5 | bookworm | 1.10.8+repack1-1 | vulnerable |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | hdf5 | source | sid | (unfixed) | unimportant | Not reported | Not reported |
| Debian | hdf5 | source | forky | (unfixed) | unimportant | Not reported | Not reported |
| Debian | hdf5 | source | trixie | (unfixed) | unimportant | Not reported | Not reported |
| Debian | hdf5 | source | bookworm | (unfixed) | unimportant | Not reported | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [hdf5-helpers]Affected
Source package: [hdf5]
Details (2)
1.10.8+repack1-1· amd64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
1.10.8+repack1-1· arm64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
- [hdf5-tools]Affected
Source package: [hdf5]
Details (2)
1.10.8+repack1-1· amd64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
1.10.8+repack1-1· arm64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
- [libhdf5-103]Affected
Source package: [hdf5]
Details (2)
1.10.8+repack1-1· amd64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
1.10.8+repack1-1· arm64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
- [libhdf5-103-1]Affected
Source package: [hdf5]
Details (2)
1.10.8+repack1-1· amd64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
1.10.8+repack1-1· arm64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
- [libhdf5-cpp-103]Affected
Source package: [hdf5]
Details (2)
1.10.8+repack1-1· amd64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
1.10.8+repack1-1· arm64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
- [libhdf5-cpp-103-1]Affected
Source package: [hdf5]
Details (2)
1.10.8+repack1-1· amd64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
1.10.8+repack1-1· arm64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
- [libhdf5-dev]Affected
Source package: [hdf5]
Details (2)
1.10.8+repack1-1· amd64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
1.10.8+repack1-1· arm64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
- [libhdf5-doc]Affected
Source package: [hdf5]
Details (2)
1.10.8+repack1-1· all · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
1.10.8+repack1-1· all · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
- [libhdf5-fortran-102]Affected
Source package: [hdf5]
Details (2)
1.10.8+repack1-1· amd64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
1.10.8+repack1-1· arm64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
- [libhdf5-hl-100]Affected
Source package: [hdf5]
Details (2)
1.10.8+repack1-1· amd64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
1.10.8+repack1-1· arm64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
- [libhdf5-hl-cpp-100]Affected
Source package: [hdf5]
Details (2)
1.10.8+repack1-1· amd64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
1.10.8+repack1-1· arm64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
- [libhdf5-hl-fortran-100]Affected
Source package: [hdf5]
Details (2)
1.10.8+repack1-1· amd64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
1.10.8+repack1-1· arm64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
- [libhdf5-java]Affected
Source package: [hdf5]
Details (2)
1.10.8+repack1-1· all · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
1.10.8+repack1-1· all · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
- [libhdf5-jni]Affected
Source package: [hdf5]
Details (2)
1.10.8+repack1-1· amd64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
1.10.8+repack1-1· arm64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
- [libhdf5-mpich-103]Affected
Source package: [hdf5]
Details (2)
1.10.8+repack1-1· amd64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
1.10.8+repack1-1· arm64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
- [libhdf5-mpich-103-1]Affected
Source package: [hdf5]
Details (2)
1.10.8+repack1-1· amd64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
1.10.8+repack1-1· arm64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
- [libhdf5-mpich-cpp-103-1]Affected
Source package: [hdf5]
Details (2)
1.10.8+repack1-1· amd64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
1.10.8+repack1-1· arm64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
- [libhdf5-mpich-dev]Affected
Source package: [hdf5]
Details (2)
1.10.8+repack1-1· amd64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
1.10.8+repack1-1· arm64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
- [libhdf5-mpich-fortran-102]Affected
Source package: [hdf5]
Details (2)
1.10.8+repack1-1· amd64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
1.10.8+repack1-1· arm64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
- [libhdf5-mpich-hl-100]Affected
Source package: [hdf5]
Details (2)
1.10.8+repack1-1· amd64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
1.10.8+repack1-1· arm64 · bookwormAffected
nvd · hdf5 · debian · bookworm; nvd · hdf5 · debian · 12
Observed:
References
- [https://github.com/HDFGroup/hdf5/issues/6489]
- [https://github.com/HDFGroup/hdf5/issues/6492]
- [https://github.com/HDFGroup/hdf5/pull/6497]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-19027]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-19027]
- [https://security-tracker.debian.org/tracker/CVE-2026-19027]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-19027.json]
[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]