CVE-2018-1061: Canonical Ubuntu Linux

High severity, CVSS 7.5. EPSS: 4.9% chance of exploitation in the next 30 days.

python before versions 2.7.15, 3.4.9, 3.5.6rc1, 3.6.5rc1 and 3.7.0 is vulnerable to catastrophic backtracking in the difflib.IS_LINE_JUNK method. An attacker could use this flaw to cause denial of service.

Affected products

• Canonical Ubuntu Linux: version 12.04 only; version 14.04 only; version 16.04 only; version 18.04 only
• Debian Debian Linux: version 8.0 only; version 9.0 only
• Fedoraproject Fedora: version 28 only; version 29 only; version 30 only
• Python Python: before 2.7.15 (fixed in 2.7.15); from 3.0, before 3.4.9 (fixed in 3.4.9); from 3.5.0, up to and including 3.5.5; from 3.6, up to and including 3.6.4; version 3.7.0 only
• Red Hat Ansible Tower: version 3.3 only
• Red Hat Enterprise Linux Desktop: version 7.0 only
• Red Hat Enterprise Linux Server: version 7.0 only
• Red Hat Enterprise Linux Workstation: version 7.0 only

Published 2018-06-19. Last modified 2026-06-17.