id: PYSEC-2026-2191
published: "2026-06-10T22:16:55.503Z"
modified: "2026-07-13T05:49:18.525020Z"
aliases:
- CVE-2026-10143
- GHSA-2jcm-hq8r-84wx
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.
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: {}
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
- type: ADVISORY
  url: https://github.com/advisories/GHSA-2jcm-hq8r-84wx
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