Suricata is a network IDS, IPS and NSM engine. Prior to versions 7.0.15 and 8.0.4, specially crafted traffic can cause Suricata to slow down, affecting performance in IDS mode. This issue has been patched in versions 7.0.15 and 8.0.4.
https://redmine.openinfosecfoundation.org/issues/8272
https://github.com/OISF/suricata/security/advisories/GHSA-hvp5-gpr6-j4gp