{"id":"CVE-2026-45820","sourceIdentifier":"22e2d327-25fe-45d7-9f0c-dcd23b7108df","published":"2026-07-22T08:16:23.280","lastModified":"2026-10-24T17:10:00.220","vulnStatus":"Analyzed","cveTags":[],"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."},{"lang":"es","value":"fflate hasta la versión 0.8.2 es vulnerable a denegación de servicio a través de un bucle infinito en unzipSync(). Un archivo ZIP manipulado con una entrada de directorio central que declara compressed_size=0xFFFFFFFF (centinela ZIP64) pero que carece de la etiqueta de campo extra ZIP64 0x0001 requerida provoca que z64e() entre en un bucle indefinido debido a lecturas fuera de límites que devuelven undefined, lo que se convierte en 0, manteniendo la condición del bucle permanentemente verdadera."}],"affected":[{"source":"22e2d327-25fe-45d7-9f0c-dcd23b7108df","affectedData":[{"vendor":"101arrowz","product":"fflate","defaultStatus":"unaffected","platforms":["Linux","macOS","Windows"],"versions":[{"version":"0.4.5","lessThanOrEqual":"0.4.8","versionType":"semver","status":"affected"},{"version":"0.5.0","lessThanOrEqual":"0.5.3","versionType":"semver","status":"affected"},{"version":"0.6.0","lessThanOrEqual":"0.6.10","versionType":"semver","status":"affected"},{"version":"0.7.0","lessThanOrEqual":"0.7.4","versionType":"semver","status":"affected"},{"version":"0.8.0","lessThanOrEqual":"0.8.2","versionType":"semver","status":"affected"}]}]}],"metrics":{"cvssMetricV40":[{"source":"22e2d327-25fe-45d7-9f0c-dcd23b7108df","type":"Secondary","cvssData":{"version":"4.0","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/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","baseScore":6.6,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"UNREPORTED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NEGLIGIBLE","Automatable":"YES","Recovery":"USER","valueDensity":"DIFFUSE","vulnerabilityResponseEffort":"MODERATE","providerUrgency":"AMBER"}}],"cvssMetricV31":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-07-22T12:53:26.309456Z","id":"CVE-2026-45820","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"22e2d327-25fe-45d7-9f0c-dcd23b7108df","type":"Secondary","description":[{"lang":"en","value":"CWE-400"},{"lang":"en","value":"CWE-835"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:101arrowz:fflate:*:*:*:*:*:node.js:*:*","versionEndIncluding":"0.8.2","matchCriteriaId":"333D4003-1B80-4B59-A091-E01AE7A6A237"}]}]}],"references":[{"url":"https://github.com/101arrowz/fflate/blob/f7873560ad229c22c4b23b06c6a3806ffde77569/src/index.ts#L2714","source":"22e2d327-25fe-45d7-9f0c-dcd23b7108df","tags":["Patch"]},{"url":"https://www.npmjs.com/package/fflate","source":"22e2d327-25fe-45d7-9f0c-dcd23b7108df","tags":["Product"]}]}