CVE-2026-45820
Summary
| CVE | CVE-2026-45820 |
|---|---|
| State | PUBLISHED |
| Assigner | seal |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-22 08:16:23 UTC |
| Updated | 2026-07-22 14:17:19 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 6.6 MEDIUM from 22e2d327-25fe-45d7-9f0c-dcd23b7108df
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
EPSS: 0.002550000 probability, percentile 0.170790000 (date 2026-07-22)
Problem Types: CWE-400 | CWE-835 | CWE-835 CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop') | CWE-400 CWE-400 Uncontrolled Resource Consumption
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | 22e2d327-25fe-45d7-9f0c-dcd23b7108df | Secondary | 6.6 | MEDIUM | 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/C... |
| 4.0 | CNA | CVSS | 6.6 | MEDIUM | 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... |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
NonePrivileges Required
NoneUser Interaction
NoneConfidentiality
NoneIntegrity
NoneAvailability
HighSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS: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
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | 101arrowz | Fflate | affected 0.4.5 0.4.8 semver | Linux, macOS, Windows |
| CNA | 101arrowz | Fflate | affected 0.5.0 0.5.3 semver | Linux, macOS, Windows |
| CNA | 101arrowz | Fflate | affected 0.6.0 0.6.10 semver | Linux, macOS, Windows |
| CNA | 101arrowz | Fflate | affected 0.7.0 0.7.4 semver | Linux, macOS, Windows |
| CNA | 101arrowz | Fflate | affected 0.8.0 0.8.2 semver | Linux, macOS, Windows |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.npmjs.com/package/fflate | 22e2d327-25fe-45d7-9f0c-dcd23b7108df | www.npmjs.com | |
| github.com/101arrowz/fflate/blob/f7873560ad229c22c4b23b06c6a3806ffde7756... | 22e2d327-25fe-45d7-9f0c-dcd23b7108df | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Seal Security (en)
There are currently no legacy QID mappings associated with this CVE.