# CVE-2026-80427

## Summary

- **CVE ID:** CVE-2026-80427
- **Severity:** HIGH
- **CVSS Score:** 8.6 (CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N)
- **CWE:** CWE-88
- **Published:** Aug 26, 2026
- **Last Modified:** Aug 29, 2026

## Description

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.

## Affected Products

- nfriedly — bestzip (0)
- nfriedly — bestzip (3.0.0)

## References

- [CNA](https://github.com/nfriedly/node-bestzip)
- [CNA](https://github.com/nfriedly/node-bestzip/security/advisories/GHSA-p87m-9567-rgcc)
- [CNA](https://www.npmjs.com/package/bestzip)
- [CNA](https://www.vulncheck.com/advisories/bestzip-before-2.2.6-and-3.0-x-before-3.0.2-argument-injection-via-missing-option-delimiter)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.15%
- **EPSS Percentile:** 4.7

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._