Client freeze via unbounded SCRAM iteration count
Published Jun 10, 2026 · Updated Jun 10, 2026
Denial of service in kafka-python before 2.3.2 allows remote attackers to freeze Kafka clients through SCRAM authentication. ScramClient.process_server_first_message() sends the broker-controlled iteration count to hashlib.pbkdf2_hmac() without an upper bound. The client must use SCRAM with a malicious broker or man-in-the-middle attacker; blocking halts sends, polls, administration, and heartbeats and can evict consumers.
Summary
What happened
Denial of service in kafka-python before 2.3.2 allows remote attackers to freeze Kafka clients through SCRAM authentication. ScramClient.process_server_first_message() sends the broker-controlled iteration count to hashlib.pbkdf2_hmac() without an upper bound. The client must use SCRAM with a malicious broker or man-in-the-middle attacker; blocking halts sends, polls, administration, and heartbeats and can evict consumers.
The record
- CVE
- CVE-2026-10143
- Published
- Jun 10, 2026
- Updated
- Jun 10, 2026
- Vendor
- Dana Powers
- Product
- kafka-python
- Classifications
- CWE-400, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 10, 2026CVE publishedPublication date reported by the CVE source.
- Jun 10, 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?
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- Affected versionversion=0 <2.3.2
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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