CVE-2026-49982

Summary

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.

Affected Software

Weaknesses

• CWE-20: CWE-20: Improper Input Validation
• CWE-22: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

ADP Enrichment

CISA ADP Vulnrichment

• SSVC:
• Exploitation: poc
  • Automatable: yes
  • Technical Impact: partial

Additional References

• https://github.com/raszi/node-tmp/security/advisories/GHSA-7c78-jf6q-g5cm

References

• https://github.com/raszi/node-tmp/security/advisories/GHSA-7c78-jf6q-g5cm

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