CVE-2026-74581
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 versions
Linux kernel versions
5.10.84,
5.15.7,
5.4.164,
5.16
and later are affected. Fixed in
5.10.265,
5.15.216,
6.1.183,
6.6.151,
6.12.103,
6.18.44,
7.1.8,
7.2
and their respective stable series.
References
8 totalFrequently asked questions
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What is CVE-2026-74581?
CVE-2026-74581 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 5.10.84 onward and has been patched in 5.10.265, 5.15.216, 6.1.183 and others. CVE-2026-74581 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-74581?
Yes. CVE-2026-74581 has been patched. Fixed versions include 5.10.265, 5.15.216, 6.1.183 and others. If you are running Linux kernel 5.10.84 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-74581 actively exploited?
No. CVE-2026-74581 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.