CVE-2026-72421ipv4: fib: Don't ignore error route in local/main tables.
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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In the Linux kernel, the following vulnerability has been resolved: ipv4: fib: Don't ignore error route in local/main tables. When CONFIG_IP_MULTIPLE_TABLES is enabled but no rule is added, fib_lookup() performs route lookup directly on two tables. Since the first lookup does not properly bail out, the result of an error route in the merged local/main table could be overwritten by another route in the default table: # unshare -n # ip link set lo up # ip route add 192.168.0.0/24 dev lo table 253 # ip route add unreachable 192.168.0.0/24 # ip route get 192.168.0.1 192.168.0.1 dev lo table default uid 0 cache <local> Once a random rule is added, the error route is respected: # ip rule add table 0 # ip rule del table 0 # ip route get 192.168.0.1 RTNETLINK answers: No route to host Let's fix the inconsistent behaviour.
- CVSS
- 10.0 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Received
- Record last updated
- Oct 16, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from f4530fa574df4d833506c53697ed1daa0d390bf4 before a29e95fbc51e8a1b932773fd0e259b2080881443; from f4530fa574df4d833506c53697ed1daa0d390bf4 before 5ae18d87a45698e8244d0fcba64c658c35a7dd3d; from f4530fa574df4d833506c53697ed1daa0d390bf4 before 9127589aabdee588278e8d0d0bd3709a760a92c8; from f4530fa574df4d833506c53697ed1daa0d390bf4 before 49eaf1403201357762d745a35882fb734107d763; from f4530fa574df4d833506c53697ed1daa0d390bf4 before fd25996f57a95d56bc568c89b4921edcf334b7d8; from f4530fa574df4d833506c53697ed1daa0d390bf4 before 828fad4fd418bcdb9f5d66fec0d184c52a85ec31; from f4530fa574df4d833506c53697ed1daa0d390bf4 before a668fa160247d7bbe921548cb845f607b8b9305f; from f4530fa574df4d833506c53697ed1daa0d390bf4 before b72f0db64205d9ce462038ba995d5d31eff32dc1 | CNA record |
References
- https://git.kernel.org/stable/c/a29e95fbc51e8a1b932773fd0e259b2080881443
- https://git.kernel.org/stable/c/5ae18d87a45698e8244d0fcba64c658c35a7dd3d
- https://git.kernel.org/stable/c/9127589aabdee588278e8d0d0bd3709a760a92c8
- https://git.kernel.org/stable/c/49eaf1403201357762d745a35882fb734107d763
- https://git.kernel.org/stable/c/fd25996f57a95d56bc568c89b4921edcf334b7d8
- https://git.kernel.org/stable/c/828fad4fd418bcdb9f5d66fec0d184c52a85ec31
- https://git.kernel.org/stable/c/a668fa160247d7bbe921548cb845f607b8b9305f
- https://git.kernel.org/stable/c/b72f0db64205d9ce462038ba995d5d31eff32dc1
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.