PYSEC-2026-2191

Dashboard / Vulnerabilities / PYSEC-2026-2191

PYSEC-2026-2191

Summary:

Details: 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.

References: https://access.redhat.com/security/cve/CVE-2026-10143, https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-10143.json, https://access.redhat.com/errata/RHSA-2026:28571, https://access.redhat.com/errata/RHSA-2026:30076, https://access.redhat.com/errata/RHSA-2026:33683, https://bugzilla.redhat.com/show_bug.cgi?id=2487722, https://github.com/dpkp/kafka-python/commit/6e4831444f972d169cdd11f5c8d50333cea3f19b, https://github.com/dpkp/kafka-python/pull/3019, https://github.com/dpkp/kafka-python/pull/3026, https://www.vulncheck.com/advisories/kafka-python-prior-to-dos-via-scram-iteration-count-in-scram-py, https://github.com/advisories/GHSA-2jcm-hq8r-84wx