Process hang via zero-step sequence loop
Published Mar 27, 2026 · Updated Mar 27, 2026
Resource exhaustion in Julian Gruber brace-expansion affected releases allows attackers to hang a process via a zero-step numeric range. Sequence generation computes the absolute step as zero, then increments the loop variable by zero while the bound test stays true, allocating results until a RangeError occurs. Reachability requires a calling application to pass an attacker-controlled string to expand(); the blocked event loop and heap growth interrupt that process.
Summary
What happened
Resource exhaustion in Julian Gruber brace-expansion affected releases allows attackers to hang a process via a zero-step numeric range. Sequence generation computes the absolute step as zero, then increments the loop variable by zero while the bound test stays true, allocating results until a RangeError occurs. Reachability requires a calling application to pass an attacker-controlled string to expand(); the blocked event loop and heap growth interrupt that process.
The record
- CVE
- CVE-2026-33750
- Published
- Mar 27, 2026
- Updated
- Mar 27, 2026
- Vendor
- Julian Gruber
- Product
- brace-expansion
- Classifications
- CWE-400, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 27, 2026CVE publishedPublication date reported by the CVE source.
- Mar 27, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 1.1.13
- Affected versionversion=>= 2.0.0, < 2.0.3
- Affected versionversion=>= 3.0.0, < 3.0.2
- Affected versionversion=>= 4.0.0, < 5.0.5
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Zero-step brace-pattern demonstrationproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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