CVE-2026-37460
frr: FRRouting: Denial of Service via crafted BGP UPDATE message
Severity
ImportantRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · June 3, 2026
Updated · August 3, 2026
Description
A flaw was found in FRRouting (FRR). Missing input validation in the rfapiRibBi2Ri() function allows a remote attacker to cause a Denial of Service (DoS) by sending a specially crafted BGP (Border Gateway Protocol) UPDATE message. This vulnerability can disrupt network services managed by FRR.
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.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
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.
CVSS / CWE
CVSS 3.1 · 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE-1286 · Improper Validation of Syntactic Correctness of Input