brace-expansion: DoS via unbounded intermediate arrays, bypassing the CVE-2026-14257 mitigation

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

• juliangruber brace-expansionbefore 1.1.18
• juliangruber brace-expansion2.0.0 and later · before 2.1.4
• juliangruber brace-expansion3.0.0 and later · before 3.0.6
• juliangruber brace-expansion4.0.0 and later · before 5.0.9

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

• juliangruber brace-expansion

  • < 1.1.18, >= 2.0.0, < 2.1.4, >= 3.0.0, < 3.0.6, >= 4.0.0, < 5.0.9affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Other highest-scoring records for the same primary product.

• CVE-2026-102278brace-expansion: DoS via uncontrolled recursion on nested brace groups causing stack exhaustion
  30Monitor
• CVE-2026-102276brace-expansion: DoS via uncontrolled recursion in parseCommaParts causing stack exhaustion
  30Monitor
• CVE-2026-14257brace-expansion DoS via unbounded expansion length causing an out-of-memory process crash
  30Monitor
• CVE-2026-13149brace-expansion through 5.0.6 is vulnerable to denial of service.
  30Monitor
• CVE-2026-45149brace-expansion: Large numeric range defeats documented `max` DoS protection
  30Monitor
• CVE-2026-33750brace-expansion: Zero-step sequence causes process hang and memory exhaustion
  30Monitor

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Root cause

Code that parses nested structures sets no depth or size limit. A small input can turn into a disproportionate processing load.

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

1function expand(node) {2  return node.children.map(expand);3}

1const MAX_DEPTH = 32;2function expand(node, depth = 0) {3  if (depth > MAX_DEPTH) throw new Error("too deep");4  return node.children.map((c) => expand(c, depth + 1));5}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.