{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-19028","assignerOrgId":"0253b833-3e77-4dfe-9d57-17db1a2f0a74","state":"PUBLISHED","assignerShortName":"HDFG","dateReserved":"2026-08-05T22:14:41.781Z","datePublished":"2026-08-05T23:15:09.580Z","dateUpdated":"2026-10-06T20:32:52.600Z"},"containers":{"cna":{"providerMetadata":{"orgId":"0253b833-3e77-4dfe-9d57-17db1a2f0a74","shortName":"HDFG","dateUpdated":"2026-10-06T20:32:52.600Z"},"title":"HDF5 integer underflow in Fletcher32 filter leads to massive out-of-bounds read","problemTypes":[{"descriptions":[{"lang":"en","cweId":"CWE-190","description":"CWE-190 Integer overflow or wraparound","type":"CWE"}]},{"descriptions":[{"lang":"en","cweId":"CWE-125","description":"CWE-125 Out-of-bounds read","type":"CWE"}]},{"descriptions":[{"lang":"en","cweId":"CWE-1284","description":"CWE-1284 Improper validation of specified quantity in input","type":"CWE"}]}],"affected":[{"vendor":"The HDF Group","product":"HDF5","versions":[{"status":"affected","version":"<=2.3.0"}],"defaultStatus":"unaffected"}],"descriptions":[{"lang":"en","value":"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.","supportingMedia":[{"type":"text/html","base64":false,"value":"H5Z__filter_fletcher32 in H5Zfletcher32.c in HDF5 prior to&nbsp;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.<br><br><br>"}]}],"references":[{"url":"https://github.com/HDFGroup/hdf5/pull/6497"},{"url":"https://github.com/HDFGroup/hdf5/issues/6488"},{"url":"https://github.com/HDFGroup/hdf5/issues/6490"}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"LOCAL","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"NONE","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":6.8,"vectorString":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/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/6488","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-06T14:24:48.048981Z","id":"CVE-2026-19028","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":"2026-08-06T14:25:52.038Z"}}]}}