Answer in brief
CVE-2026-72421 records a Critical severity (CVSS 10.0) vulnerability in ipv4: fib: Don't ignore error route in local/main tables.. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 10.0. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=f4530fa574df4d833506c53697ed1daa0d390bf4 <a29e95fbc51e8a1b932773fd0e259b2080881443 || >=f4530fa574df4d833506c53697ed1daa0d390bf4 <5ae18d87a45698e8244d0fcba64c658c35a7dd3d || >=f4530fa574df4d833506c53697ed1daa0d390bf4 <9127589aabdee588278e8d0d0bd3709a760a92c8 || >=f4530fa574df4d833506c53697ed1daa0d390bf4 <49eaf1403201357762d745a35882fb734107d763 || >=f4530fa574df4d833506c53697ed1daa0d390bf4 <fd25996f57a95d56bc568c89b4921edcf334b7d8 || >=f4530fa574df4d833506c53697ed1daa0d390bf4 <828fad4fd418bcdb9f5d66fec0d184c52a85ec31 || >=f4530fa574df4d833506c53697ed1daa0d390bf4 <a668fa160247d7bbe921548cb845f607b8b9305f || >=f4530fa574df4d833506c53697ed1daa0d390bf4 <b72f0db64205d9ce462038ba995d5d31eff32dc1 | a29e95fbc51e8a1b932773fd0e259b2080881443, 5ae18d87a45698e8244d0fcba64c658c35a7dd3d, 9127589aabdee588278e8d0d0bd3709a760a92c8, 49eaf1403201357762d745a35882fb734107d763, fd25996f57a95d56bc568c89b4921edcf334b7d8, 828fad4fd418bcdb9f5d66fec0d184c52a85ec31, a668fa160247d7bbe921548cb845f607b8b9305f, b72f0db64205d9ce462038ba995d5d31eff32dc1 |
| Linux/Linuxgeneric | 3.6 | Not reported |
Published upstream
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 15, 2026
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.
Quoted source text, attributed separately from HOL analysis.