CVE-2026-74581
CriticalCVSS 9.8Exploitation Probability (EPSS)
Low risk6th percentile - higher than 6% of all known CVEs
Summary
In the Linux kernel, the fib6_rule_suppress() function (IPv6 routing) does not clear the res->rt6 pointer after dropping a route, which can lead to use of a freed rt6_info object and trigger rcuref_put_slowpath() during release.
Risk Assessment
Risk of use-after-free in the IPv6 stack, potentially leading to system crash or unpredictable routing behavior.
Recommendation
Apply the Linux kernel patch that clears res->rt6 when suppressing the route to prevent use of the released pointer.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: net: ipv6: clear suppressed fib6 rule result fib6_rule_suppress() drops a suppressed route with ip6_rt_put_flags(), but leaves res->rt6 pointing at the released rt6_info. If no later rule supplies a replacement, fib6_rule_lookup() still sees res.rt6 and returns that stale dst to its caller. A suppressing rule can therefore leak a released route back to rt6_lookup(), and the next put hits rcuref_put_slowpath() from dst_release(). Clear res->rt6 when suppressing the route so suppressed lookups fall through to the null dst instead of reusing the released one.