kafka-python prior to 2.3.2 contains a denial-of-service vulnerability in the protocol parser that allows a malicious broker or machine-in-the-middle attacker to exhaust memory or hang connections by sending a crafted 4-byte frame length value without bounds validation. Attackers can send a specially crafted frame length through the receive_bytes() function to trigger either a multi-gigabyte memory allocation or an uncaught ValueError that leaves the connection in a broken state, causing requests to hang and consumers to stop heartbeating until restart.
https://github.com/dpkp/kafka-python/pull/3026
https://github.com/dpkp/kafka-python/pull/3019
https://github.com/dpkp/kafka-python/commit/6e4831444f972d169cdd11f5c8d50333cea3f19b
Published: 2026-06-10
Updated: 2026-06-11
Base Score: 7.8
Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C
Severity: High
Base Score: 7.5
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Severity: High
Base Score: 8.7
Vector: 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
Severity: High
EPSS: 0.00042