{"id":"GHSA-65x3-rw7q-gx94","summary":"multiparty vulnerable to ReDoS via filename parsing","details":"### Impact\n\nmultiparty@4.2.3 and lower versions are vulnerable to denial of service via regular expression backtracking in the `Content-Disposition` filename parameter parser. A multipart upload with a long header value containing `!filename=\"1` repeated can cause regex matching to take seconds, blocking the event loop. Any service accepting multipart uploads via multiparty is affected.\n\n### Patches\n\nUsers should upgrade to multiparty@4.3.0 or higher.\n\n### Workarounds\n\nNone. Limiting upload sizes at the proxy/gateway layer reduces but does not eliminate the attack surface, since a small ~8 KB header is sufficient to trigger the vulnerable backtracking.\n\n### Resources\n\n- [OWASP: Regular expression Denial of Service (ReDoS)](https://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS)","aliases":["CVE-2026-8159"],"modified":"2026-05-18T17:45:09.415312979Z","published":"2026-05-18T17:40:10Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2026-05-18T17:40:10Z","nvd_published_at":"2026-05-12T10:16:48Z","cwe_ids":["CWE-1333"],"severity":"HIGH"},"references":[{"type":"WEB","url":"https://github.com/pillarjs/multiparty/security/advisories/GHSA-65x3-rw7q-gx94"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-8159"},{"type":"WEB","url":"https://cna.openjsf.org/security-advisories.html"},{"type":"PACKAGE","url":"https://github.com/pillarjs/multiparty"},{"type":"WEB","url":"https://github.com/pillarjs/multiparty/releases/tag/v4.3.0"},{"type":"WEB","url":"https://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS"}],"affected":[{"package":{"name":"multiparty","ecosystem":"npm","purl":"pkg:npm/multiparty"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"4.3.0"}]}],"database_specific":{"last_known_affected_version_range":"\u003c= 4.2.3","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-65x3-rw7q-gx94/GHSA-65x3-rw7q-gx94.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}