{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-19027","assignerOrgId":"0253b833-3e77-4dfe-9d57-17db1a2f0a74","state":"PUBLISHED","assignerShortName":"HDFG","dateReserved":"2026-08-05T22:14:41.114Z","datePublished":"2026-08-05T23:12:20.658Z","dateUpdated":"2026-10-06T20:33:19.385Z"},"containers":{"cna":{"providerMetadata":{"orgId":"0253b833-3e77-4dfe-9d57-17db1a2f0a74","shortName":"HDFG","dateUpdated":"2026-10-06T20:33:19.385Z"},"title":"HDF5 out-of-bounds heap read in N-Bit filter decompression","problemTypes":[{"descriptions":[{"lang":"en","cweId":"CWE-125","description":"CWE-125 Out-of-bounds read","type":"CWE"}]}],"affected":[{"vendor":"The HDF Group","product":"HDF5","versions":[{"status":"affected","version":"<=2.3.0"}],"defaultStatus":"unaffected"}],"descriptions":[{"lang":"en","value":"The H5Z__nbit_decompress_one_byte, H5Z__nbit_decompress_one_nooptype, and H5Z__nbit_decompress_one_atomic functions in H5Znbit.c in HDF5\nprior 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.","supportingMedia":[{"type":"text/html","base64":false,"value":"The H5Z__nbit_decompress_one_byte, H5Z__nbit_decompress_one_nooptype, and H5Z__nbit_decompress_one_atomic functions in H5Znbit.c in HDF5\nprior 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.<br><br><br>"}]}],"references":[{"url":"https://github.com/HDFGroup/hdf5/pull/6497"},{"url":"https://github.com/HDFGroup/hdf5/issues/6489"},{"url":"https://github.com/HDFGroup/hdf5/issues/6492"}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"LOCAL","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"LOW","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"MEDIUM","baseScore":6.9,"vectorString":"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"}}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"Vulnogram 1.0.4"}},"adp":[{"references":[{"url":"https://github.com/HDFGroup/hdf5/issues/6489","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-06T14:29:51.698432Z","id":"CVE-2026-19027","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-08-06T14:30:48.955Z"}}]}}