7.5
High
CVE-2026-10143 kafka-python prior to 2.3.2 DoS via SCRAM Iteration Count in scram.py
Description
kafka-python prior to 2.3.2 contains a denial-of-service vulnerability in SCRAM authentication handling that allows a malicious or machine-in-the-middle broker to freeze the client event loop by supplying an excessively large iteration count. In scram.py, ScramClient.process_server_first_message() passes the broker-controlled SCRAM iteration count directly to hashlib.pbkdf2_hmac() without validation, blocking producer sends, consumer polls, admin operations, and heartbeats, which can cause consumer group eviction and repeated reconnect failures.
CVSS 3.1 detail
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitable remotely over the network, without an account and without any user action; an attacker can seriously compromise confidentiality, integrity or availability.
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- Interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| kafka-python | Versions not published | |
| Red Hat Quay 3.12 1781937357 | earliest → < 1781937357 | 1781937357 |
| Red Hat Quay 3.9 1781878070 | earliest → < 1781878070 | 1781878070 |
| Red Hat Quay 3 | Versions not published | |
| Red Hat Quay 3.10 1782487717 | earliest → < 1782487717 | 1782487717 |
| Red Hat Quay 3.16 1783955846 | earliest → < 1783955846 | 1783955846 |
| Red Hat Quay 3.1 1782487717 | earliest → < 1782487717 | 1782487717 |
| Red Hat Quay 3.15 1784351966 | earliest → < 1784351966 | 1784351966 |