CPU exhaustion via quadratic regex backtracking
Published Jun 9, 2025 · Updated Jun 11, 2025
Regular expression denial of service in Julian Gruber brace-expansion allows remote authenticated users to interrupt consuming services. The expand function tests trailing text with the greedy /,.*}/ expression, which retries from successive commas when no closing brace exists and consumes quadratic CPU time. The calling application must pass attacker-controlled brace text to expand; the public proof of concept uses 100,000 commas followed by a nonmatching character to exhaust CPU.
Summary
What happened
Regular expression denial of service in Julian Gruber brace-expansion allows remote authenticated users to interrupt consuming services. The expand function tests trailing text with the greedy /,.*}/ expression, which retries from successive commas when no closing brace exists and consumes quadratic CPU time. The calling application must pass attacker-controlled brace text to expand; the public proof of concept uses 100,000 commas followed by a nonmatching character to exhaust CPU.
The record
- CVE
- CVE-2025-5889
- Published
- Jun 9, 2025
- Updated
- Jun 11, 2025
- Vendor
- Julian Gruber
- Product
- brace-expansion
- Classifications
- CWE-1333, CWE-400, T1499.004
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 9, 2025CVE publishedPublication date reported by the CVE source.
- Jun 11, 2025Record 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=1.1.0
- Affected versionversion=1.1.1
- Affected versionversion=1.1.10
- Affected versionversion=1.1.11
- Affected versionversion=1.1.2
- Affected versionversion=1.1.3
- Affected versionversion=1.1.4
- Affected versionversion=1.1.5
- Affected versionversion=1.1.6
- Affected versionversion=1.1.7
- Affected versionversion=1.1.8
- Affected versionversion=1.1.9
- Affected versionversion=2.0.0
- Affected versionversion=2.0.1
- Affected versionversion=3.0
- Affected versionversion=4.0
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
- ReDos in brace-expansion poc.jsproof of concept · unverified
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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