{"id":"CVE-2026-45820","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.","modified":"2026-07-25T03:56:32.296652820Z","published":"2026-07-22T06:57:13.726Z","database_specific":{"unresolved_ranges":[{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"0.5.0"},{"last_affected":"0.5.3"},{"introduced":"0.6.0"},{"last_affected":"0.6.10"}]}],"cna_assigner":"seal","cwe_ids":["CWE-400","CWE-835"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45820.json"},"references":[{"type":"WEB","url":"https://github.com/101arrowz/fflate/blob/f7873560ad229c22c4b23b06c6a3806ffde77569/src/index.ts#L2714"},{"type":"WEB","url":"https://www.npmjs.com/package/fflate"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45820.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45820"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/101arrowz/fflate","events":[{"introduced":"0"},{"fixed":"d3243651cb142e3e04f3e4bc037b9e985878f444"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"0.8.2"}],"source":"DESCRIPTION"}}],"versions":["v0.8.0","v0.7.4","v0.7.2","v0.7.1","v0.7.0","v0.6.9","v0.6.4","v0.6.3","v0.6.0","v0.5.2","v0.4.8"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-45820.json"}}],"schema_version":"1.7.5","severity":[{"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"}]}