CVE-2026-13149

A flaw was found in brace-expansion. An attacker can exploit a vulnerability in the expand() function by providing a specially crafted string. This string, containing consecutive non-expanding brace groups, can trigger exponential-time complexity, leading to significant CPU consumption and event-loop blocking. This can result in a Denial of Service (DoS) for the affected system.

A flaw was found in brace-expansion, a widely-used npm package for expanding brace sequences. The expand() function exhibits exponential-time complexity when processing consecutive non-expanding brace groups. An attacker who can supply crafted input to expand(), directly or transitively via minimatch or glob, can cause significant CPU consumption and event-loop blocking, resulting in denial of service. The max option does not mitigate this issue, as it bounds the output size rather than the recursion work.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

There is no practical mitigation for this vulnerability. The brace-expansion package is typically a transitive dependency pulled in via minimatch and glob, making it difficult to isolate. Users should upgrade to a fixed version of brace-expansion when one becomes available.