{"id":"CVE-2026-118370","published":"2026-10-28T03:17:13.293","lastModified":"2026-10-28T15:21:31.673","description":"libexpat through 2.9.0 contains a signed integer overflow vulnerability in storeAtts() in lib/xmlparse.c that allows attackers to trigger out-of-bounds writes via oversized attribute counts. Attackers can supply a multi-gigabyte document with a start tag carrying over 2^30 attributes to overflow attIndex and nPrefixes, crashing applications or corrupting heap memory.","cvssScore":5.9,"cvssSeverity":"MEDIUM","cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","cwes":["CWE-190"],"vendors":[],"products":[],"references":[{"url":"https://github.com/libexpat/libexpat","tags":[]},{"url":"https://github.com/libexpat/libexpat/blob/a76b1174c1ea52abb639a4c69d52b630a8a106a2/expat/lib/xmlparse.c#L4138-L4140","tags":[]},{"url":"https://github.com/libexpat/libexpat/commit/1bac53c4fc460a03cd9860f39501c7979f6750ae","tags":[]},{"url":"https://github.com/libexpat/libexpat/commit/621cb2c78b253ee023a86bc91d6ddb048481c04c","tags":[]},{"url":"https://github.com/libexpat/libexpat/pull/1450","tags":[]},{"url":"https://www.vulncheck.com/advisories/libexpat-through-2.9.0-integer-overflow-in-storeatts-via-attindex-and-nprefixes","tags":[]}],"exploitRefs":[{"url":"https://github.com/libexpat/libexpat","tags":[]},{"url":"https://github.com/libexpat/libexpat/blob/a76b1174c1ea52abb639a4c69d52b630a8a106a2/expat/lib/xmlparse.c#L4138-L4140","tags":[]},{"url":"https://github.com/libexpat/libexpat/commit/1bac53c4fc460a03cd9860f39501c7979f6750ae","tags":[]},{"url":"https://github.com/libexpat/libexpat/commit/621cb2c78b253ee023a86bc91d6ddb048481c04c","tags":[]},{"url":"https://github.com/libexpat/libexpat/pull/1450","tags":[]}],"hasPoc":true,"ai":null}