CVE-2026-33750

brace-expansion: Zero-step sequence causes process hang and memory exhaustion

State: Published
Severity: 6.5 Medium
Published: Mar 27, 2026
Updated: Mar 27, 2026
Reserved: Mar 23, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	6.5 Medium	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H	GitHub_M

Weaknesses

CWE-400 Uncontrolled Resource Consumption

Affected Products

Product	Versions
brace-expansionjuliangruber	>= 4.0.0, < 5.0.5Affected >= 3.0.0, < 3.0.2Affected >= 2.0.0, < 2.0.3Affected < 1.1.13Affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.