HIGH7.5
GHSA-px8p-9vwx-vf98
fflate unzipSync can enter an infinite loop when parsing malformed ZIP64 archives
Quick fix
GHSA-px8p-9vwx-vf98 — fflate: upgrade to the fixed version with the command below.
npm install fflate@0.4.9Details
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.
Are you affected?
Enter the version of the package you're using.
Affected packages
References
- https://nvd.nist.gov/vuln/detail/CVE-2026-45820[ADVISORY]
- https://github.com/101arrowz/fflate/commit/e6d5e6e1076892f72770ac732d83c81da9f3316e[WEB]
- https://github.com/101arrowz/fflate[PACKAGE]
- https://github.com/101arrowz/fflate/blob/f7873560ad229c22c4b23b06c6a3806ffde77569/src/index.ts#L2714[WEB]
- https://github.com/101arrowz/fflate/releases/tag/v0.8.3[WEB]