{"id":"CVE-2026-120755","title":"Integer Underflow Leads to Out-of-Bounds Read via Truncated Chunk in HDF5 Szip Filter","summary":"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 fir…","severity":"medium","cvss":4.7,"cvssVector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P","cvssSource":"cna","cwe":["CWE-125"],"vendor":"The HDF Group","product":"Szip Filter","affected":["szip_filter < 2.3.0"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-03T15:43:28.018929Z"},"published":"2026-11-03","updated":"2026-11-03","sourceUpdated":"2026-11-03T15:43:43.838Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-120755","references":[{"url":"https://github.com/HDFGroup/hdf5/pull/6585"}],"tags":["cve.org"],"epss":0.0014,"epssPercentile":0.03367,"ingestedAt":"2026-11-05T20:33:06.273Z","slug":"CVE-2026-120755","body":"## Overview\n\nHDF5 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 the end of the chunk buffer. An attacker who can get a user or application to read a dataset from a crafted HDF5 file can cause a denial of service. Only builds with szip support (libaec or the szip library) are affected.\n\n## Affected\n\n- `szip_filter < 2.3.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":26,"depthScoreParts":{"impact":25.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}