CVE-2026-37460

Red Hat statement

This Important flaw in FRRouting (FRR) allows a remote, unauthenticated attacker to trigger a denial of service by sending a specially crafted BGP UPDATE message. This can lead to the disruption of network services managed by FRR instances configured to handle BGP traffic. The vulnerability does not require complex attack vectors or user interaction, making it a significant availability risk for affected systems.

Red Hat mitigation

To mitigate this issue, restrict access to FRRouting's BGP services to only trusted peers and networks. Implement firewall rules to limit inbound connections to BGP port 179 (TCP) to known, legitimate BGP neighbors. If BGP is not actively used, consider disabling the BGP daemon within FRR to eliminate the attack surface. Warning: Modifying firewall rules or FRR configuration may impact network connectivity and requires careful planning and testing. A restart of the FRR service may be required for changes to take effect.