{"id":"CVE-2026-117610","title":"libexpat through 2.9.0 NULL Pointer Dereference via External Entity Subparser","summary":"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 empt…","severity":"medium","cvss":5.9,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"cna","cwe":["CWE-476"],"vendor":"libexpat","product":"libexpat","affected":["libexpat <= 2.9.0"],"published":"2026-10-28","updated":"2026-10-28","sourceUpdated":"2026-10-28T02:03:18.766Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-117610","references":[{"url":"https://github.com/libexpat/libexpat/pull/1444"},{"url":"https://github.com/libexpat/libexpat/commit/7b0d50e4b1d16fafd55876260701e04279a7489d"},{"url":"https://github.com/libexpat/libexpat/blob/a76b1174c1ea52abb639a4c69d52b630a8a106a2/expat/lib/xmlparse.c#L3468-L3510"},{"url":"https://github.com/libexpat/libexpat"},{"url":"https://www.vulncheck.com/advisories/libexpat-through-2.9.0-null-pointer-dereference-via-external-entity-subparser","label":"VulnCheck Advisory: libexpat through 2.9.0 NULL Pointer Dereference via External Entity Subparser"}],"tags":["cve.org"],"ingestedAt":"2026-10-28T03:02:57.626Z","slug":"CVE-2026-117610","body":"## Overview\n\nlibexpat 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.\n\n## Affected\n\n- `libexpat <= 2.9.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":32,"depthScoreParts":{"impact":32.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}