CVE-2026-89790

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A divide-by-zero issue exists in the IPv6 implementation. The rt6 multipath rebalance() function calculates the total eligible nexthop weight in an initial pass and programs upper bounds in a subsequent pass. Because RTM NEWROUTE is RTNL-free, a concurrent ignore routes with linkdown update can cause the first pass to return zero while the second pass identifies an eligible nexthop. This sequence leads the rt6 upper bound set() function to perform a division by zero.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.