CVE-2021-31806: Debian Linux

Medium severity, CVSS 6.5. EPSS: 95.8% chance of exploitation in the next 30 days.

An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to a memory-management bug, it is vulnerable to a Denial of Service attack (against all clients using the proxy) via HTTP Range request processing.

Affected products

• Debian Debian Linux: version 9.0 only; version 10.0 only
• Fedoraproject Fedora: version 33 only; version 34 only
• Netapp Cloud Manager: affected versions not specified
• Squid-Cache Squid: before 4.15 (fixed in 4.15); from 5.0, before 5.0.6 (fixed in 5.0.6)

Published 2021-05-27. Last modified 2026-06-17.