CVE-2020-11653: Debian Linux

High severity, CVSS 7.5. EPSS: 2.2% chance of exploitation in the next 30 days.

An issue was discovered in Varnish Cache before 6.0.6 LTS, 6.1.x and 6.2.x before 6.2.3, and 6.3.x before 6.3.2. It occurs when communication with a TLS termination proxy uses PROXY version 2. There can be an assertion failure and daemon restart, which causes a performance loss.

Affected products

• Debian Debian Linux: version 10.0 only
• Opensuse Backports Sle: version 15.0 only
• Opensuse Leap: version 15.1 only
• Varnish-Cache Varnish Cache: from 6.1.0, before 6.2.3 (fixed in 6.2.3); from 6.3.0, before 6.3.2 (fixed in 6.3.2)
• Varnish-Software Varnish Cache: from 6.0.0, before 6.0.6 (fixed in 6.0.6)

Published 2020-04-08. Last modified 2026-06-17.