{"id":"CVE-2026-45820","aliases":["CLSA-2026-1789897715","CLSA-2026-1790161290","EUVD-2026-47616","GHSA-px8p-9vwx-vf98"],"status":"published","title":"fflate unzipSync can enter an infinite loop when parsing malformed ZIP64 archives","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.","severity":{"version":"4.0","score":6.6,"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","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00279,"percentile":0.20469,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-400","CWE-835"],"published":"2026-07-22T06:57:13Z","modified":"2026-10-28T02:31:14Z","fixes":[{"ecosystem":"npm","package":"fflate","fixed_in":["0.4.9","0.5.4","0.6.11","0.7.5","0.8.3"],"sources":["ghsa","osv"]},{"ecosystem":"TuxCare:npm","package":"fflate","fixed_in":["0.8.2-tuxcare.1","0.8.1-tuxcare.1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"fflate","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.4.5"},{"fixed":"0.4.9"}]}]},{"source":"ghsa","ecosystem":"npm","package":"fflate","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.5.0"},{"fixed":"0.5.4"}]}]},{"source":"ghsa","ecosystem":"npm","package":"fflate","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.6.0"},{"fixed":"0.6.11"}]}]},{"source":"ghsa","ecosystem":"npm","package":"fflate","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.7.0"},{"fixed":"0.7.5"}]}]},{"source":"ghsa","ecosystem":"npm","package":"fflate","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.8.0"},{"fixed":"0.8.3"}]}]},{"source":"osv","ecosystem":"TuxCare:npm","package":"fflate","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.8.2-tuxcare.0"},{"fixed":"0.8.2-tuxcare.1"}]}],"versions":["0.8.2"]},{"source":"osv","ecosystem":"TuxCare:npm","package":"fflate","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.8.1-tuxcare.0"},{"fixed":"0.8.1-tuxcare.1"}]}],"versions":["0.8.1"]},{"source":"osv","ecosystem":"npm","package":"fflate","ranges":[{"type":"SEMVER","events":[{"introduced":"0.4.5"},{"fixed":"0.4.9"}]}]},{"source":"osv","ecosystem":"npm","package":"fflate","ranges":[{"type":"SEMVER","events":[{"introduced":"0.5.0"},{"fixed":"0.5.4"}]}]},{"source":"osv","ecosystem":"npm","package":"fflate","ranges":[{"type":"SEMVER","events":[{"introduced":"0.6.0"},{"fixed":"0.6.11"}]}]},{"source":"osv","ecosystem":"npm","package":"fflate","ranges":[{"type":"SEMVER","events":[{"introduced":"0.7.0"},{"fixed":"0.7.5"}]}]},{"source":"osv","ecosystem":"npm","package":"fflate","ranges":[{"type":"SEMVER","events":[{"introduced":"0.8.0"},{"fixed":"0.8.3"}]}]}],"products":[{"vendor":"101arrowz","product":"fflate"}],"references":[{"url":"https://github.com/101arrowz/fflate/blob/f7873560ad229c22c4b23b06c6a3806ffde77569/src/index.ts#L2714","tags":["Patch","web"]},{"url":"https://www.npmjs.com/package/fflate","tags":["Product","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45820","tags":["advisory"]},{"url":"https://github.com/101arrowz/fflate/commit/e6d5e6e1076892f72770ac732d83c81da9f3316e","tags":["web"]},{"url":"https://github.com/101arrowz/fflate/releases/tag/v0.8.3","tags":["web"]},{"url":"https://github.com/advisories/GHSA-px8p-9vwx-vf98"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45820.json","tags":["advisory"]},{"url":"https://github.com/101arrowz/fflate","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-45820","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.","status":"published","published":"2026-07-22T06:57:13.726Z","modified":"2026-07-22T12:53:38.246Z","cvss":[{"version":"4.0","score":6.6,"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","level":"medium","assessor":"cna"}],"cwes":["CWE-835","CWE-400"],"updated_at":"2026-11-02T13:46:43.922571Z"}],"euvd":[{"id":"EUVD-2026-47616","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.","status":"published","published":"2026-07-22T06:57:13Z","modified":"2026-07-22T12:53:38Z","cvss":[{"version":"4.0","score":6.6,"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","level":"medium"}],"updated_at":"2026-11-02T18:19:46.900828Z"}],"ghsa":[{"id":"GHSA-px8p-9vwx-vf98","title":"fflate unzipSync can enter an infinite loop when parsing malformed ZIP64 archives","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.","status":"published","published":"2026-07-22T09:32:13Z","modified":"2026-09-03T14:58:15Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"},{"version":"4.0","score":6.6,"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","level":"medium"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:41:11.621873Z"}],"nvd":[{"id":"CVE-2026-45820","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.","status":"published","published":"2026-07-22T08:16:23.28Z","modified":"2026-10-24T17:10:00.22Z","cvss":[{"version":"4.0","score":6.6,"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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:N/AU:Y/R:U/V:D/RE:M/U:Amber","level":"medium","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary"}],"cwes":["CWE-400","CWE-835"],"updated_at":"2026-11-02T14:12:32.089897Z"}],"osv":[{"id":"CVE-2026-45820","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.","status":"published","published":"2026-07-22T06:57:13.726Z","modified":"2026-10-28T02:31:14.828911543Z","cvss":[{"version":"4.0","score":6.6,"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","level":"medium"}],"cwes":["CWE-400","CWE-835"],"updated_at":"2026-11-02T15:45:05.525666Z"},{"id":"GHSA-px8p-9vwx-vf98","title":"fflate unzipSync can enter an infinite loop when parsing malformed ZIP64 archives","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.","status":"published","published":"2026-07-22T09:32:13Z","modified":"2026-09-10T03:50:52.758792289Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"},{"version":"4.0","score":6.6,"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","level":"medium"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T15:46:53.700556Z"},{"id":"CLSA-2026-1789897715","title":"TuxCare security update for fflate (1 CVE)","description":"TuxCare rebuilt fflate to address 1 CVE. Fixed in 0.8.2-tuxcare.1.","status":"published","published":"2026-09-20T09:48:35Z","modified":"2026-10-15T09:46:02.153091164Z","updated_at":"2026-11-02T15:43:48.28229Z"},{"id":"CLSA-2026-1790161290","title":"TuxCare security update for fflate (1 CVE)","description":"TuxCare rebuilt fflate to address 1 CVE. Fixed in 0.8.1-tuxcare.1.","status":"published","published":"2026-09-23T11:01:30Z","modified":"2026-10-15T09:47:14.555172963Z","updated_at":"2026-11-02T15:43:48.28229Z"}]}}