CVE-2026-45820

MEDIUM

101arrowz Fflate - Uncontrolled Resource Consumption

Title source: rule
STIX 2.1

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.

Scores

CVSS v4 6.6
EPSS 0.0026
EPSS Percentile 17.1%
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

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-400 CWE-835
Status published
Products (5)
101arrowz/fflate 0.4.5 - 0.4.8
101arrowz/fflate 0.5.0 - 0.5.3
101arrowz/fflate 0.6.0 - 0.6.10
101arrowz/fflate 0.7.0 - 0.7.4
101arrowz/fflate 0.8.0 - 0.8.2
Published Jul 22, 2026
Tracked Since Jul 22, 2026