{"id":"GHSA-px8p-9vwx-vf98","summary":"fflate unzipSync can enter an infinite loop when parsing malformed ZIP64 archives","details":"fflate through 0.8.2 is vulnerable to denial of service via an infinite loop in unzipSync(). A crafted ZIP archive with a central directory entry declaring compressed_size=0xFFFFFFFF (ZIP64 sentinel) but missing the required ZIP64 extra field tag 0x0001 causes z64e() to loop indefinitely due to out-of-bounds reads returning undefined, which coerces to 0, keeping the loop condition permanently true.","aliases":["CVE-2026-45820"],"modified":"2026-09-03T15:26:05.755451Z","published":"2026-07-22T09:32:13Z","database_specific":{"github_reviewed_at":"2026-09-03T14:58:12Z","nvd_published_at":"2026-07-22T08:16:23Z","cwe_ids":["CWE-400"],"severity":"MODERATE","github_reviewed":true},"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45820"},{"type":"WEB","url":"https://github.com/101arrowz/fflate/commit/e6d5e6e1076892f72770ac732d83c81da9f3316e"},{"type":"PACKAGE","url":"https://github.com/101arrowz/fflate"},{"type":"WEB","url":"https://github.com/101arrowz/fflate/blob/f7873560ad229c22c4b23b06c6a3806ffde77569/src/index.ts#L2714"},{"type":"WEB","url":"https://github.com/101arrowz/fflate/releases/tag/v0.8.3"}],"affected":[{"package":{"name":"fflate","ecosystem":"npm","purl":"pkg:npm/fflate"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.4.5"},{"fixed":"0.4.9"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-px8p-9vwx-vf98/GHSA-px8p-9vwx-vf98.json"}},{"package":{"name":"fflate","ecosystem":"npm","purl":"pkg:npm/fflate"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.5.0"},{"fixed":"0.5.4"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-px8p-9vwx-vf98/GHSA-px8p-9vwx-vf98.json"}},{"package":{"name":"fflate","ecosystem":"npm","purl":"pkg:npm/fflate"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.6.0"},{"fixed":"0.6.11"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-px8p-9vwx-vf98/GHSA-px8p-9vwx-vf98.json"}},{"package":{"name":"fflate","ecosystem":"npm","purl":"pkg:npm/fflate"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.7.0"},{"fixed":"0.7.5"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-px8p-9vwx-vf98/GHSA-px8p-9vwx-vf98.json"}},{"package":{"name":"fflate","ecosystem":"npm","purl":"pkg:npm/fflate"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.8.0"},{"fixed":"0.8.3"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-px8p-9vwx-vf98/GHSA-px8p-9vwx-vf98.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"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/S:N/AU:Y/R:U/V:D/RE:M/U:Amber"}]}