CVE-2026-72421

CVE-2026-72421: critical vulnerability affecting the affected product. Check CVSS, KEV status, business impact and recommended administrator actions.
CVE-2026-72421CVSS 10.0Linux

CVE-2026-72421

CVE-2026-72421: critical vulnerability affecting the affected product. Check CVSS, KEV status, business impact and recommended administrator actions.

CVSS
10.0 CRITICAL
EPSS
45.12%
Known exploited
not in KEV
Product
-

What is known

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.

Business impact

Successful exploitation of CVE-2026-72421, a critical vulnerability (CVSS 10.0) affecting the affected product, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration.

Recommended administrator action

Confirm whether the affected product is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.

Sources

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