CVE-2026-45820
Full vulnerability record from the local CVENow database.
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
MEDIUM
CVSS score
6.6
(v4.0)
Vulnerability status
Analyzed
Source identifier
22e2d327-25fe-45d7-9f0c-dcd23b7108df
Published
2026-07-22 08:16:23.280000
Last modified
2026-10-24 17:10:00.220000
View original CVE JSON
{
"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": [],
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{
"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": [
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"macOS",
"Windows"
],
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"exploitMaturity": "UNREPORTED",
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"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",
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"valueDensity": "DIFFUSE",
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"id": "CVE-2026-45820",
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"references": [
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"source": "22e2d327-25fe-45d7-9f0c-dcd23b7108df",
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