Critical severity · published Aug 21, 2026
CVE-2026-74581
net: ipv6: clear suppressed fib6 rule result
9.8
CVSS
0.4%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 36% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
Linux · Linux
209d35ee34e25f9668c404350a1c86d914c54ffa before 90c57310e266eb94e4a80d6b15a9ca131d2e82cb; 8ef8a76a340ebdb2c2eea3f6fb0ebbed09a16383 before 5d29b286c9de0b309e94b9ed083aa1a2f429434f; cdef485217d30382f3bf6448c54b4401648fe3f1 before 354db6243eca59e9d187ffbf8b7955b044ce84dc; cdef485217d30382f3bf6448c54b4401648fe3f1 before 6d98c70fe0ba8c7708bfd5b2a5174d2086775daa; cdef485217d30382f3bf6448c54b4401648fe3f1 before 9bad152c42b37499162367fe47867411e62fffa3; cdef485217d30382f3bf6448c54b4401648fe3f1 before dc3ab04220667f254f4348572b2a0b3febff89fb; +7 more · source: vendor