CVE-2026-45149 MEDIUM

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

Vendor Juliangruber
Product brace-expansion
Weakness CWE-400
Published May 29, 2026
Last update June 1, 2026

CVSS base score

6.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction Required
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

May 29, 2026 CVE published
June 1, 2026 Record updated