CVE-2021-42391: Clickhouse

Medium severity, CVSS 6.5. EPSS: 1.4% chance of exploitation in the next 30 days.

Divide-by-zero in Clickhouse's Gorilla compression codec when parsing a malicious query. The first byte of the compressed buffer is used in a modulo operation without being checked for 0.

Affected products

• Clickhouse Clickhouse: before 21.10.2.15 (fixed in 21.10.2.15)

Published 2022-03-14. Last modified 2026-06-17.