Brace-expansion: infinite loop on zero step, fixed in 5.0.5/3.0.2/2.0.3/1.1.13
CVE-2026-33750 Published on March 27, 2026
brace-expansion: Zero-step sequence causes process hang and memory exhaustion
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.
Vulnerability Analysis
CVE-2026-33750 is exploitable with network access, requires user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
What is a Resource Exhaustion Vulnerability?
The software does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.
CVE-2026-33750 has been classified to as a Resource Exhaustion vulnerability or weakness.
Affected Versions
juliangruber brace-expansion:- Version >= 4.0.0, < 5.0.5 is affected.
- Version >= 3.0.0, < 3.0.2 is affected.
- Version >= 2.0.0, < 2.0.3 is affected.
- Version < 1.1.13 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.