Vulnerability in Nfriedly Bestzip
CVE-2026-80427
bestzip builds the argument list for the system zip utility without separating options from operands. The destination archive path and the caller-supplied source paths are passed to the child process with no -- delimiter between them, so any source entry beginning with a hyphen is interpreted by zip as an option rather than a file name. zip accepts -T to test the finished archive and -TT to name the command used to perform that test, so a source list containing those two entries and a command string causes zip to run that command through a shell once the archive has been written. An application that passes a file name or path it received from an untrusted source into the bestzip API therefore executes a command of the supplier's choosing. Versions 2.2.6 and 3.0.2 add the delimiter.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.4 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.002 (10.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 11th percentile — 10.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.001
Affected products
Weakness classification (CWE)
References
- github.com/nfriedly/node-bestzip (product)
- github.com/nfriedly/node-bestzip/security/advisories/GHSA-p87m-9567-rgcc (vendor-advisory)
- www.npmjs.com/package/bestzip (product)
- www.vulncheck.com/advisories/bestzip-before-2.2.6-and-3.0-x-before-3.0.2-argume… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-80427?
- CVE-2026-80427 is a high-severity vulnerability in Nfriedly Bestzip, classified under Argument Injection. CVSS score: 8.4/10. Published 2026-08-26.
- How severe is CVE-2026-80427?
- High severity. CVSS v3 base score is 8.4 out of 10.