{"id":"CVE-2026-45820","state":"PUBLISHED","title":"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=0xFFFFFF","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.","publishedAt":"2026-07-22T06:57:13.726Z","updatedAt":"2026-07-22T12:53:38.246Z","severity":{"score":6.6,"label":"Medium","version":"4.0","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","source":"seal"},"assigner":"seal","products":["101arrowz fflate"],"affected":[{"vendor":"101arrowz","product":"fflate","defaultStatus":"unaffected","versions":[{"version":"0.4.5","status":"affected","lessThanOrEqual":"0.4.8","versionType":"semver"},{"version":"0.5.0","status":"affected","lessThanOrEqual":"0.5.3","versionType":"semver"},{"version":"0.6.0","status":"affected","lessThanOrEqual":"0.6.10","versionType":"semver"},{"version":"0.7.0","status":"affected","lessThanOrEqual":"0.7.4","versionType":"semver"},{"version":"0.8.0","status":"affected","lessThanOrEqual":"0.8.2","versionType":"semver"}],"platforms":["Linux","macOS","Windows"]}],"references":["https://github.com/101arrowz/fflate/blob/f7873560ad229c22c4b23b06c6a3806ffde77569/src/index.ts#L2714","https://www.npmjs.com/package/fflate"],"weaknesses":["CWE-835","CWE-400"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/45xxx/CVE-2026-45820.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-45820","state":"PUBLISHED","datePublished":"2026-07-22T06:57:13.726Z","dateUpdated":"2026-07-22T12:53:38.246Z","assignerShortName":"seal","assignerOrgId":"22e2d327-25fe-45d7-9f0c-dcd23b7108df","dateReserved":"2026-05-13T12:03:13.544Z"},"containers":{"cna":{"descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"101arrowz","product":"fflate","defaultStatus":"unaffected","versions":[{"version":"0.4.5","status":"affected","lessThanOrEqual":"0.4.8","versionType":"semver"},{"version":"0.5.0","status":"affected","lessThanOrEqual":"0.5.3","versionType":"semver"},{"version":"0.6.0","status":"affected","lessThanOrEqual":"0.6.10","versionType":"semver"},{"version":"0.7.0","status":"affected","lessThanOrEqual":"0.7.4","versionType":"semver"},{"version":"0.8.0","status":"affected","lessThanOrEqual":"0.8.2","versionType":"semver"}],"platforms":["Linux","macOS","Windows"]}],"references":[{"url":"https://github.com/101arrowz/fflate/blob/f7873560ad229c22c4b23b06c6a3806ffde77569/src/index.ts#L2714"},{"url":"https://www.npmjs.com/package/fflate"}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"NONE","exploitMaturity":"UNREPORTED","Safety":"NEGLIGIBLE","Automatable":"YES","Recovery":"USER","valueDensity":"DIFFUSE","vulnerabilityResponseEffort":"MODERATE","providerUrgency":"AMBER","version":"4.0","baseSeverity":"MEDIUM","baseScore":6.6,"vectorString":"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"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-835","lang":"en","description":"CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')","type":"CWE"},{"cweId":"CWE-400","lang":"en","description":"CWE-400 Uncontrolled Resource Consumption","type":"CWE"}]}],"providerMetadata":{"shortName":"seal","orgId":"22e2d327-25fe-45d7-9f0c-dcd23b7108df","dateUpdated":"2026-07-22T06:57:13.726Z"},"impacts":[{"capecId":"CAPEC-469","descriptions":[{"lang":"en","value":"CAPEC-469 HTTP DoS"}]}],"credits":[{"lang":"en","value":"Seal Security","type":"finder"}],"source":{"discovery":"INTERNAL"},"x_generator":{"engine":"Vulnogram 1.0.2"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-22T12:53:26.309456Z","id":"CVE-2026-45820","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-22T12:53:38.246Z"}}]}}}