Answer in brief
CVE-2026-19028 records a Medium severity (CVSS 6.8) vulnerability in HDF5 integer underflow in Fletcher32 filter leads to massive out-of-bounds read. The current sources do not mark it as known exploited. The current feed maps The HDF Group/HDF5 (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 6.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps The HDF Group/HDF5 (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| The HDF Group/HDF5generic | <=2.3.0 | Not reported |
Published upstream
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
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.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-19028 records a Medium severity (CVSS 6.8) vulnerability in HDF5 integer underflow in Fletcher32 filter leads to massive out-of-bounds read. The current sources do not mark it as known exploited. The current feed maps The HDF Group/HDF5 (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 6.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps The HDF Group/HDF5 (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| The HDF Group/HDF5generic | <=2.3.0 | Not reported |
Published upstream
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
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.
Quoted source text, attributed separately from HOL analysis.