A flaw was found in FRRouting (FRR). An unauthenticated remote attacker can exploit an integer underflow vulnerability by supplying a specially crafted BGP (Border Gateway Protocol) UPDATE message. This issue can lead to a Denial of Service (DoS).

This vulnerability allows an unauthenticated remote attacker to cause a denial of service via a specially crafted BGP UPDATE message. Due to this reason, this issue has been rated with an important severity. Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible. Red Hat Enterprise Linux 10 Affected frr Red Hat Enterprise Linux 8 Affected frr Red Hat Enterprise Linux 9 Affected frr Red Hat Enterprise Linux 9 Affected frr10 https://www.cve.org/CVERecord?id=CVE-2026-37459 https://nvd.nist.gov/vuln/detail/CVE-2026-37459 https://github.com/FRRouting/frr/commit/693a2e02687cdc9d16501275e05136edea9650d9