{"cve":"CVE-2026-45820","nvd":{"published":"2026-07-22T08:16:23.280","modified":"2026-10-24T17:10:00.220","status":"Analyzed","description":"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.","cvss_v4":{"vector":"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","score":6.6},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-400","CWE-835"],"references":["https://github.com/101arrowz/fflate/blob/f7873560ad229c22c4b23b06c6a3806ffde77569/src/index.ts#L2714","https://www.npmjs.com/package/fflate"],"products":["101arrowz:fflate"],"source":"nvd","synced_at":"2026-10-25T17:50:08.599881581+00:00"},"epss":{"cve":"CVE-2026-45820","score":0.00279,"percentile":0.20135,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-px8p-9vwx-vf98","url":"https://osv.dev/vulnerability/GHSA-px8p-9vwx-vf98","summary":"fflate unzipSync can enter an infinite loop when parsing malformed ZIP64 archives","modified":"2026-09-10T03:50:52.758792289Z","packages":[{"ecosystem":"npm","name":"fflate","purl":"pkg:npm/fflate","ranges":[">=0.4.5 <0.4.9"],"fixed":["0.4.9"]},{"ecosystem":"npm","name":"fflate","purl":"pkg:npm/fflate","ranges":[">=0.5.0 <0.5.4"],"fixed":["0.5.4"]},{"ecosystem":"npm","name":"fflate","purl":"pkg:npm/fflate","ranges":[">=0.6.0 <0.6.11"],"fixed":["0.6.11"]},{"ecosystem":"npm","name":"fflate","purl":"pkg:npm/fflate","ranges":[">=0.7.0 <0.7.5"],"fixed":["0.7.5"]},{"ecosystem":"npm","name":"fflate","purl":"pkg:npm/fflate","ranges":[">=0.8.0 <0.8.3"],"fixed":["0.8.3"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}