CVE-2026-19028
HDF5 integer underflow in Fletcher32 filter leads to massive out-of-bounds read
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
CISA's decision points: whether it is exploited, whether attacks can be automated, and how much control an attacker gets. Assessed (SSVC 2.0.3).What do these mean? →
- Exploitation: poc
- Automatable: no
- Technical impact: partial
Summary
H5Z__filter_fletcher32 in H5Zfletcher32.c in HDF5 prior to 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.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: poc · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- The HDF Group HDF5
through 2.3.0