{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-44452", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-05-06T15:49:25.192Z", "datePublished": "2026-07-16T22:54:42.914Z", "dateUpdated": "2026-07-16T22:54:42.914Z"}, "containers": {"cna": {"title": "h2o is vulnerable to heap overrun", "problemTypes": [{"descriptions": [{"cweId": "CWE-125", "lang": "en", "description": "CWE-125: Out-of-bounds Read", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-170", "lang": "en", "description": "CWE-170: Improper Null Termination", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 5.9, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}}], "references": [{"name": "https://github.com/h2o/h2o/security/advisories/GHSA-w68q-rqwx-7wvq", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/h2o/h2o/security/advisories/GHSA-w68q-rqwx-7wvq"}, {"name": "https://github.com/h2o/h2o/commit/8dc37cb1e6171f7f772667618ea440696fed82c3", "tags": ["x_refsource_MISC"], "url": "https://github.com/h2o/h2o/commit/8dc37cb1e6171f7f772667618ea440696fed82c3"}], "affected": [{"vendor": "h2o", "product": "h2o", "versions": [{"version": "< 8dc37cb", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-07-16T22:54:42.914Z"}, "descriptions": [{"lang": "en", "value": "h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. Prior to commit 8dc37cb, when h2o receives a ClientHello message over TLS or QUIC and it contains a zero-length SNI extension, the h2o server runs over the zero-length hostname while trying to copy the hostname, assuming that it is NULL-terminated. This is a potential denial-of-service attack vector in sense that it might trigger segmentation violation. This issue has been fixed by commit 8dc37cb."}], "source": {"advisory": "GHSA-w68q-rqwx-7wvq", "discovery": "UNKNOWN"}}}}

{}

{}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[0,8dc37cb)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "h2o", "source": "cna", "vendor": "h2o"}, "product": "h2o", "vendor": "h2o"}], "created": "2026-07-17T00:30:03.493276+00:00", "updated": "2026-07-17T00:30:03.493303+00:00", "vendors": ["h2o", "h2o$PRODUCT$h2o"]}