Vulnerability Description
brace-expansion through 5.0.7 is vulnerable to denial of service via memory exhaustion. The expand() function limits the number of results with a max option (default 100,000) but does not bound the length of each result string. By chaining multiple brace groups, an attacker keeps the result count under the limit while making each result progressively longer, so total memory scales with both count and string length until the process hits a fatal, uncatchable out-of-memory error. About 7.5 KB of input ('{a,b}'.repeat(1500)) crashes a default Node.js process. Any application that passes attacker-influenced strings to brace-expansion.expand() - directly or transitively via minimatch / glob brace patterns - can be crashed by a small request. Fixed in 5.0.8 by adding a maxLength option (default 4,000,000) that bounds accumulated output and intermediate arrays.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/juliangruber/brace-expansion
- https://github.com/juliangruber/brace-expansion/commit/a1bd33999ea75262c4749fff3
- https://www.npmjs.com/package/brace-expansion
FAQ
What is CVE-2026-14257?
CVE-2026-14257 is a vulnerability with a CVSS score of 7.5 (HIGH). brace-expansion through 5.0.7 is vulnerable to denial of service via memory exhaustion. The expand() function limits the number of results with a max option (default 100,000) but does not bound the le...
How severe is CVE-2026-14257?
CVE-2026-14257 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-14257?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.