In F5 BIG-IP systems 12.1.0 - 12.1.2, malicious requests made to virtual servers with an HTTP profile can cause the TMM to restart. The issue is exposed with BIG-IP APM profiles, regardless of settings. The issue is also exposed with the non-default "Normalize URI" configuration options used in iRules and/or BIG-IP LTM policies. An attacker may be able to disrupt traffic or cause the BIG-IP system to fail over to another device in the device group.
Severity
CVSS 3.0
5.9 medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
1.4% chance of exploitation in the next 30 days; higher than 72% of CVEs (scores of 2026-10-31)