CVE-2026-13149
Description
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.
Statement
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.
Mitigation
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.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU)
Attackers can create crafted inputs that intentionally cause the regular expression to use excessive backtracking in a way that causes the CPU consumption to spike.
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