Vulnerability · Published Mar 27, 2026 · Assigned by GitHub_M
CVE-2026-33750brace-expansion: Zero-step sequence causes process hang and memory exhaustion
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 0.4% (higher than 39% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
The brace-expansion library generates arbitrary strings containing a common prefix and suffix. Prior to versions 5.0.5, 3.0.2, 2.0.3, and 1.1.13, a brace pattern with a zero step value (e.g., `{1..2..0}`) causes the sequence generation loop to run indefinitely, making the process hang for seconds and allocate heaps of memory. Versions 5.0.5, 3.0.2, 2.0.3, and 1.1.13 fix the issue. As a workaround, sanitize strings passed to `expand()` to ensure a step value of `0` is not used.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | node-brace-expansion | no fix listed | DEBIAN-CVE-2026-33750 |
| Debian:13 | node-brace-expansion | no fix listed | DEBIAN-CVE-2026-33750 |
| Debian:14 | node-brace-expansion | 2.0.3+~1.1.2-1 | DEBIAN-CVE-2026-33750 |
| Ubuntu:22.04:LTS | node-brace-expansion | no fix listed | UBUNTU-CVE-2026-33750 |
| Ubuntu:24.04:LTS | node-brace-expansion | no fix listed | UBUNTU-CVE-2026-33750 |
| Ubuntu:25.10 | node-brace-expansion | no fix listed | UBUNTU-CVE-2026-33750 |
| Ubuntu:26.04:LTS | node-brace-expansion | no fix listed | UBUNTU-CVE-2026-33750 |
| Ubuntu:26.10 | node-brace-expansion | no fix listed | UBUNTU-CVE-2026-33750 |
| npm | brace-expansion | 1.1.13 | GHSA-f886-m6hf-6m8v |
| npm | brace-expansion | 2.0.3 | GHSA-f886-m6hf-6m8v |
| npm | brace-expansion | 3.0.2 | GHSA-f886-m6hf-6m8v |
| npm | brace-expansion | 5.0.5 | GHSA-f886-m6hf-6m8v |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| juliangruber | brace-expansion | >= 4.0.0, < 5.0.5>= 3.0.0, < 3.0.2>= 2.0.0, < 2.0.3< 1.1.13 |
Weakness: CWE-400 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
References
- https://github.com/juliangruber/brace-expansion/security/advisories/GHSA-f886-m6hf-6m8v x_refsource_CONFIRM
- https://github.com/juliangruber/brace-expansion/issues/98 x_refsource_MISC
- https://github.com/juliangruber/brace-expansion/pull/95 x_refsource_MISC
- https://github.com/juliangruber/brace-expansion/pull/96 x_refsource_MISC
- https://github.com/juliangruber/brace-expansion/pull/97 x_refsource_MISC
- https://github.com/juliangruber/brace-expansion/commit/311ac0d54994158c0a384e286a7d6cbb17ee8ed5 x_refsource_MISC
- https://github.com/juliangruber/brace-expansion/commit/7fd684f89fdde3549563d0a6522226a9189472a2 x_refsource_MISC
- https://github.com/juliangruber/brace-expansion/commit/b9cacd9e55e7a1fa588fe4b7bb1159d52f1d902a x_refsource_MISC
- https://github.com/juliangruber/brace-expansion/blob/daa71bcb4a30a2df9bcb7f7b8daaf2ab30e5794a/src/index.ts#L107-L113 x_refsource_MISC
- https://github.com/juliangruber/brace-expansion/blob/daa71bcb4a30a2df9bcb7f7b8daaf2ab30e5794a/src/index.ts#L184 x_refsource_MISC