{"id":"CVE-2026-117610","state":"PUBLISHED","title":"libexpat through 2.9.0 NULL Pointer Dereference via External Entity Subparser","description":"libexpat through 2.9.0 contains a NULL pointer dereference vulnerability in externalEntityInitProcessor2() in lib/xmlparse.c that mishandles the XML_TOK_NONE token from empty input. Attackers who control stream chunking can force an empty non-final first parse on an external entity subparser, causing a later parse to crash the application.","publishedAt":"2026-10-28T02:03:18.766Z","updatedAt":"2026-10-28T02:03:18.766Z","severity":{"score":8.2,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","source":"VulnCheck"},"assigner":"VulnCheck","products":["libexpat libexpat"],"affected":[{"vendor":"libexpat","product":"libexpat","packageURL":"pkg:github/libexpat/libexpat","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"2.9.0","versionType":"semver"}],"repo":"https://github.com/libexpat/libexpat"}],"references":["https://github.com/libexpat/libexpat/pull/1444","https://github.com/libexpat/libexpat/commit/7b0d50e4b1d16fafd55876260701e04279a7489d","https://github.com/libexpat/libexpat/blob/a76b1174c1ea52abb639a4c69d52b630a8a106a2/expat/lib/xmlparse.c#L3468-L3510","https://github.com/libexpat/libexpat","https://www.vulncheck.com/advisories/libexpat-through-2.9.0-null-pointer-dereference-via-external-entity-subparser"],"weaknesses":["CWE-476"],"ingestedAt":"2026-10-29T20:10:52.580Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/117xxx/CVE-2026-117610.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-117610","state":"PUBLISHED","datePublished":"2026-10-28T02:03:18.766Z","dateUpdated":"2026-10-28T02:03:18.766Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-10-27T13:04:09.906Z"},"containers":{"cna":{"title":"libexpat through 2.9.0 NULL Pointer Dereference via External Entity Subparser","descriptions":[{"lang":"en","value":"libexpat through 2.9.0 contains a NULL pointer dereference vulnerability in externalEntityInitProcessor2() in lib/xmlparse.c that mishandles the XML_TOK_NONE token from empty input. Attackers who control stream chunking can force an empty non-final first parse on an external entity subparser, causing a later parse to crash the application."}],"affected":[{"vendor":"libexpat","product":"libexpat","packageURL":"pkg:github/libexpat/libexpat","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"2.9.0","versionType":"semver"}],"repo":"https://github.com/libexpat/libexpat"}],"references":[{"url":"https://github.com/libexpat/libexpat/pull/1444","tags":["patch","issue-tracking"]},{"url":"https://github.com/libexpat/libexpat/commit/7b0d50e4b1d16fafd55876260701e04279a7489d","tags":["patch"]},{"url":"https://github.com/libexpat/libexpat/blob/a76b1174c1ea52abb639a4c69d52b630a8a106a2/expat/lib/xmlparse.c#L3468-L3510","tags":["technical-description"]},{"url":"https://github.com/libexpat/libexpat","tags":["product"]},{"url":"https://www.vulncheck.com/advisories/libexpat-through-2.9.0-null-pointer-dereference-via-external-entity-subparser","name":"VulnCheck Advisory: libexpat through 2.9.0 NULL Pointer Dereference via External Entity Subparser","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.2,"baseSeverity":"HIGH"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH","baseScore":5.9,"baseSeverity":"MEDIUM"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-476","lang":"en","description":"NULL Pointer Dereference","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-10-28T02:03:18.766Z"},"datePublic":"2026-10-26T00:00:00.000Z","cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:*","versionEndIncluding":"2.9.0"}]}]}],"credits":[{"lang":"en","value":"Minkyung Park","type":"finder"},{"lang":"en","value":"Sebastian Pipping","type":"remediation developer"}],"x_generator":{"engine":"vulncheck-endgame"}}}}}