Inefficient Algorithmic Complexity in brace-expansion - CVE-2026-13149
Published: June 29, 2026
Vulnerability identifier: #VU135820
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-13149
CWE-ID: CWE-407
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Julian Gruber
Affected software:
brace-expansion
brace-expansion
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to inefficient algorithmic complexity in expand() when processing attacker-influenced brace expansion patterns containing consecutive non-expanding {} groups. A remote attacker can send a specially crafted input string to cause a denial of service.
The issue can block the calling thread for minutes or indefinitely with a small all-ASCII input, and applications using Node's single-threaded event loop may fully stall a worker or process.
How to mitigate CVE-2026-13149
Install security update from vendor's website.