PatchTheCVECVE-2026-120755: HDF5 through 2.2.0 contains an out-of-bounds read vulnerability in H5Z__filter_szip() in src/H5Zszip.c
CVE-2026-120755 is a medium-severity flaw (CVSS 5.5) affecting hdf5. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
HDF5 through 2.2.0 contains an out-of-bounds read vulnerability in H5Z__filter_szip() in src/H5Zszip.c. When decoding a szip-compressed chunk, the function subtracts the 4-byte uncompressed-length header from the chunk length without first verifying that the chunk is at least 4 bytes long. A truncated or corrupted chunk shorter than the header causes the length calculation to wrap around to a very large value, and the decompressor reads far past
Why this priority
- No elevated risk signals yet
A fixed release or distro patch exists.
Risk facts
| CVSS score | 5.5 (Medium) |
| Attack vector | Local |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | Required |
| EPSS exploit chance | n/a |
| CISA exploited list | No |
| Weakness | CWE-125 |
| Published | 2026-11-03 |
| Last modified | 2026-11-03 |
Last updated 2026-11-03 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Advisories and coverage
Research and news
- VulDB Recent Entries: CVE-2026-120755 | HDF Group HDF5 up to 2.2.x Szip Filter src/H5Zszip.c H5Z__filter_szip out-of-bounds 2026-11-03
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-120755?
hdf5: upgrade to newer than 2.2.0. Exact commands for each OS are on this page.
Is CVE-2026-120755 being exploited?
CVE-2026-120755 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-120755 affect?
CVE-2026-120755 affects hdf5. Severity is medium (CVSS 5.5). HDF5 through 2.2.0 contains an out-of-bounds read vulnerability in H5Z__filter_szip() in src/H5Zszip.c. When decoding a szip-compressed chunk, the function subtracts the 4-byte uncompressed-length header from the chunk length without first
How urgent is CVE-2026-120755?
Priority 19/100. No elevated risk signals yet.
Related CVEs
- CVE-2026-120754 LOW 3.3 UPGRADE HDF5 through 2.2.0 contains an uninitialized memory read vulnerability in H5Z__filter_scaleoffset() in src/H5Z
- CVE-2026-120756 MEDIUM 6.1 UPGRADE HDF5 through 2.2.0 contains a heap buffer over-read vulnerability in H5O__chunk_deserialize() in src/H5Ocache.
- CVE-2026-120757 HIGH 7.1 UPGRADE HDF5 through 2.2.0 contains a heap buffer over-read vulnerability in H5L__extern_traverse() in src/H5Lexternal
- CVE-2026-120758 MEDIUM 5.5 UPGRADE HDF5 through 2.2.0 contains a NULL pointer dereference vulnerability in H5HL_unprotect() in src/H5HL.c
- CVE-2026-34734 HIGH 7.8 UPGRADE HDF5 is software for managing data