A buffer overflow flaw in Open vSwitch allows a remote attacker to send a specially crafted EPASV command longer than 255 characters over an FTP stream. The malformed command triggers a heap access error that crashes the user‑space datapath, causing a denial of service on the affected system. The weakness is classified as a buffer overflow (CWE‑120).

Red Hat Enterprise Linux 7, 8 and 9 running the Fast Datapath user‑space datapath, Red Hat OpenShift Container Platform 4, and Red Hat OpenStack Platform releases 13 (Queens), 16.2, 17.1, and 18.0 are listed as vulnerable. No specific patch levels are provided in the advisory, so any installed instance of these products that enables conntrack FTP helpers over the user‑space datapath is potentially affected.

The CVSS score is 5.9, indicating a moderate impact. No EPSS score is available to quantify exploitation likelihood, and the vulnerability is not listed in the CISA KEV catalog, suggesting no publicly known exploit is active. Nonetheless, an attacker who can establish an FTP session to the target and has a conntrack flow configured for FTP helpers can inject the oversized EPASV command to trigger a crash. The attack requires remote network access with FTP traffic allowed, and presumably the use of the user‑space datapath. The lack of a KEV listing and the moderate CVSS suggest a reasonable but not urgent threat; however, disruption of network services may be critical for operational environments.