tmp is a temporary file and directory creator for node.js. In version 0.2.6, the _assertPath guard added to tmp rejects only string values that contain the substring ... It is bypassed when prefix, postfix, or template is supplied as a non-string value (Array, Buffer, or any object) whose includes('..') returns falsy but whose stringification still contains ../. The value flows through Array.prototype.join/String coercion inside _generateTmpName and path.join(tmpDir, opts.dir, name), producing a final path that escapes tmpdir and creates a file or directory at an attacker-controlled location with the host process's privileges. This affects any application that forwards untrusted request data (a common pattern is JSON body fields or qs-parsed bracket-array query strings such as ?prefix[]=...) into tmp.file, tmp.fileSync, tmp.dir, tmp.dirSync, tmp.tmpName, or tmp.tmpNameSync without explicit type coercion. This vulnerability is fixed in 0.2.7.
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://github.com/raszi/node-tmp/security/advisories/GHSA-7c78-jf6q-g5cm Exploit, Mitigation, Vendor Advisory
- https://github.com/raszi/node-tmp/security/advisories/GHSA-7c78-jf6q-g5cm Exploit, Mitigation, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 8.2 · rasziNVD modified 2026-10-26 11:10
Affected (CPE criteria) 1
cpe:2.3:a:raszi:tmp:0.2.6:*:*:*:*:node.js:*:*
References 2
- https://github.com/raszi/node-tmp/security/advisories/GHSA-7c78-jf6q-g5cm Exploit, Mitigation, Vendor Advisory
- https://github.com/raszi/node-tmp/security/advisories/GHSA-7c78-jf6q-g5cm Exploit, Mitigation, Vendor Advisory