CVE-2026-102278 brace-expansion: DoS via uncontrolled recursion on nested brace groups causing stack exhaustion

What is CVE-2026-102278?

CVE-2026-102278 is a high-severity denial of service vulnerability in juliangruber brace-expansion, published on 28 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

The brace-expansion library generates arbitrary strings containing a common prefix and suffix. Prior to 1.1.20, 2.1.6, 3.0.8, and 5.0.11, deeply nested brace groups cause expand_() to recurse once per nesting level at comma-member and single-set expansion sites, exhausting the native stack before output limits can apply and potentially terminating the Node.js process. expand_ performs uncontrolled recursion for nested brace alternatives and single-part sets. deeply nested brace groups supplied as an untrusted pattern. expand_ is affected. expand is affected. Comma members is affected. Single set is affected. native stack exhaustion during nested sub-expansion. process-terminating denial of service. This issue is fixed in versions 1.1.20, 2.1.6, 3.0.8, and 5.0.11.

Weakness: CWE-674, CWE-400

Which versions are affected by CVE-2026-102278?

8 open source packages ship an affected version, including brace-expansion.

How do I fix CVE-2026-102278?

Upgrade brace-expansion to a fixed version for your release line: 1.1.20, 2.1.6, 3.0.8 or 5.0.11.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-102278 being exploited?

There is no known exploitation of CVE-2026-102278 in the wild and no public exploit code.

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-105078, AZL-105092, AZL-105242, CLEANSTART-2026-DA12179, CLEANSTART-2026-DZ00497, CLEANSTART-2026-JT17760 and 58 more.