Vulnerability · Published May 29, 2026 · Assigned by GitHub_M

CVE-2026-45149brace-expansion: Large numeric range defeats documented `max` DoS protection

Medium 6.5

In plain English

A medium-severity uncontrolled resource consumption in brace-expansion from juliangruber. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 23% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.3%top 77.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

The brace-expansion library generates arbitrary strings containing a common prefix and suffix. From 5.0.0 to before 5.0.6, the max option was being applied too late. When expanding a single large numeric range like {1..10000000}, the sequence generation loop generates all 10 million intermediate elements before the max limit is applied With max=10, the output is correctly limited to 10 items, but the process still allocates ~505 MB and spends ~800ms building the full intermediate array. This vulnerability is fixed in 5.0.6.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12node-brace-expansionno fix listedDEBIAN-CVE-2026-45149
Debian:13node-brace-expansionno fix listedDEBIAN-CVE-2026-45149
Debian:14node-brace-expansion2.0.3+~1.1.2-3DEBIAN-CVE-2026-45149
Ubuntu:22.04:LTSnode-brace-expansionno fix listedUBUNTU-CVE-2026-45149
Ubuntu:24.04:LTSnode-brace-expansionno fix listedUBUNTU-CVE-2026-45149
Ubuntu:25.10node-brace-expansionno fix listedUBUNTU-CVE-2026-45149
Ubuntu:26.04:LTSnode-brace-expansionno fix listedUBUNTU-CVE-2026-45149
Ubuntu:26.10node-brace-expansionno fix listedUBUNTU-CVE-2026-45149
npmbrace-expansion5.0.6GHSA-jxxr-4gwj-5jf2

Affected products (as reported)

VendorProductVersions
juliangruber brace-expansion >= 5.0.0, < 5.0.6

Weakness: CWE-400 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

References