{"id":"PYSEC-2026-2191","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.","aliases":["CVE-2026-10143"],"modified":"2026-07-13T07:15:26.382573128Z","published":"2026-06-10T22:16:55.503Z","references":[{"type":"WEB","url":"https://access.redhat.com/security/cve/CVE-2026-10143"},{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-10143.json"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:28571"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:30076"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:33683"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2487722"},{"type":"FIX","url":"https://github.com/dpkp/kafka-python/commit/6e4831444f972d169cdd11f5c8d50333cea3f19b"},{"type":"FIX","url":"https://github.com/dpkp/kafka-python/pull/3019"},{"type":"FIX","url":"https://github.com/dpkp/kafka-python/pull/3026"},{"type":"FIX","url":"https://www.vulncheck.com/advisories/kafka-python-prior-to-dos-via-scram-iteration-count-in-scram-py"}],"affected":[{"package":{"name":"kafka-python","ecosystem":"PyPI","purl":"pkg:pypi/kafka-python"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.3.2"}]}],"versions":["0.9.0","0.9.1","0.9.2","0.9.3","0.9.4","0.9.5","1.0.0","1.0.1","1.0.2","1.1.0","1.1.1","1.2.0","1.2.1","1.2.2","1.2.3","1.2.4","1.2.5","1.3.0","1.3.1","1.3.2","1.3.3","1.3.4","1.3.5","1.4.0","1.4.1","1.4.2","1.4.3","1.4.4","1.4.5","1.4.6","1.4.7","2.0.0","2.0.1","2.0.2","2.0.3","2.0.4","2.0.5","2.0.6","2.1.0","2.1.1","2.1.2","2.1.3","2.1.4","2.1.5","2.1.6","2.2.0","2.2.1","2.2.10","2.2.11","2.2.12","2.2.13","2.2.14","2.2.15","2.2.16","2.2.17","2.2.18","2.2.19","2.2.2","2.2.20","2.2.3","2.2.4","2.2.5","2.2.6","2.2.7","2.2.8","2.2.9","2.3.0","2.3.1"],"ecosystem_specific":{},"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/kafka-python/PYSEC-2026-2191.yaml"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"}]}