{"id":"CVE-2026-77214","revision":"fe0b2e0f8de445858d8f5ebf6832c1ad","records":[{"revision":"fe0b2e0f8de445858d8f5ebf6832c1ad","observedAt":"2026-10-27T12:09:21.929+00:00","statement":{"source":"cve-program","id":"CVE-2026-77214","aliases":[],"title":"libexpat Heap Buffer Over-read in xmlparse.c via XML_ParseBuffer","description":"libexpat before commit 13c5f63 contains a heap buffer over-read vulnerability in xmlparse.c. XML_ParseBuffer advances the parse buffer end with parser->m_bufferEnd += len using a caller-supplied length that is not validated against the allocated buffer size, so repeated XML_ParseBuffer calls move m_bufferEnd past the end of the heap allocation and subsequent parsing reads out of bounds. Reaching this path requires a parse buffer to already be present; otherwise XML_ParseBuffer returns XML_ERROR_NO_BUFFER. A buffer is present after a prior call to XML_GetBuffer, either directly (the common case) or indirectly through a prior XML_Parse call that allocates the buffer internally. The over-read discloses adjacent heap memory to the calling application, recovering heap pointers, libc function pointers, and code pointers sufficient to defeat ASLR and build further exploitation primitives.","state":0,"publishedAt":"2026-10-07T14:35:42.794+00:00","modifiedAt":"2026-10-27T10:14:34.918+00:00","affected":[{"ecosystem":"Vendor product","name":"libexpat","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"defaultStatus\": \"unaffected\",\n                    \"vendor\": \"libexpat\",\n                    \"product\": \"libexpat\",\n                    \"packageURL\": \"pkg:github/libexpat/libexpat\",\n                    \"repo\": \"https://github.com/libexpat/libexpat\",\n                    \"versions\": [\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"0\",\n                            \"versionType\": \"semver\",\n                            \"lessThanOrEqual\": \"2.8.5\"\n                        },\n                        {\n                            \"status\": \"unaffected\",\n                            \"version\": \"13c5f63a7f1c52c2feee3b16a1134d4fb68e9ea0\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:L/SC:N/SI:N/SA:N","score":8.3,"severity":"HIGH"},{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L","score":8.2,"severity":"HIGH"}],"references":["https://github.com/libexpat/libexpat/pull/1393","https://github.com/libexpat/libexpat/commit/13c5f63a7f1c52c2feee3b16a1134d4fb68e9ea0","https://www.vulncheck.com/advisories/libexpat-heap-buffer-over-read-in-xmlparse-c-via-xml-parsebuffer"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-77214","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-77214","identifiers":["CVE-2026-77214"]},"retained":false,"historicalAffected":[]}],"coverage":[]}