CPU denial of service via quadratic grouping
Published Aug 17, 2026 · Updated Aug 17, 2026
Denial of service in sqlparse before 0.6.0 allows remote attackers to exhaust CPU via crafted deeply nested SQL input. In sqlparse/sql.py, TokenList.init and group_tokens recompute group values by flattening whole token subtrees with str(self) and str(start), so grouping nested parenthesis and CASE structures triggers repeated O(subtree) work during parse(), format(), and split(). Exposure requires an application that passes attacker-controlled SQL into those entry points, and the published impact is worker hang or severe request latency rather than code execution or data disclosure.
Summary
What happened
Denial of service in sqlparse before 0.6.0 allows remote attackers to exhaust CPU via crafted deeply nested SQL input. In sqlparse/sql.py, TokenList.init and group_tokens recompute group values by flattening whole token subtrees with str(self) and str(start), so grouping nested parenthesis and CASE structures triggers repeated O(subtree) work during parse(), format(), and split(). Exposure requires an application that passes attacker-controlled SQL into those entry points, and the published impact is worker hang or severe request latency rather than code execution or data disclosure.
The record
- CVE
- CVE-2026-54284
- Published
- Aug 17, 2026
- Updated
- Aug 17, 2026
- Vendor
- Andi Albrecht
- Product
- sqlparse
- Classifications
- CWE-1333, CWE-407, T1499.003
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 17, 2026CVE publishedPublication date reported by the CVE source.
- Aug 17, 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=< 0.6.0
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
- GHSA proof of concept for nested SQL inputproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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