CVE-2026-74581: Linux

Critical severity, CVSS 9.8. EPSS: 0.4% chance of exploitation in the next 30 days.

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.

Affected products

• Linux Linux: from 5.10.84, before 5.10.265 (fixed in 5.10.265); from 5.15.7, before 5.15.216 (fixed in 5.15.216); from 5.4.164, before 5.5 (fixed in 5.5); from 5.16, before 6.1.183 (fixed in 6.1.183); from 6.2, before 6.6.151 (fixed in 6.6.151); from 6.7, before 6.12.103 (fixed in 6.12.103); …

Published 2026-08-21. Last modified 2026-08-25.