CVE-2026-97598
In the Linux kernel, the following vulnerability has been resolved: ipv4: fib: bound automatic table ID allocation fib_empty_table() probes every table ID from 1 until it finds a free one. IPv4 tables are stored in a 256-bucket hash table, so a dense set of IDs makes each probe walk a growing hash chain while RTNL is held. Automatic table assignment ("ip rule ... table 0") is an IPv4-only legacy path. Bound the automatically allocated ID to 4096 so the RTNL hold stays bounded, without changing lookups of explicitly specified table IDs. This changes user-visible behavior. A table-0 rule previously received the lowest free ID in 1..RT_TABLE_MAX (0xFFFFFFFF). After this patch the search stops at 4096 and the rule add fails with ENOBUFS if that range is fully occupied. Explicit table IDs above 4096 remain usable. The automatic path is unused in practice: it is IPv4-only, not documented by ip-rule, uncovered by kernel selftests, and both NetworkManager and systemd refuse table 0.
Affected versions
Linux kernel versions
2.6.19
and later are affected. Fixed in
5.10.271,
5.15.222,
6.1.189,
6.6.158,
6.12.111,
6.18.53,
7.2.7,
7.3-rc3
and their respective stable series.
References
8 totalFrequently asked questions
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What is CVE-2026-97598?
CVE-2026-97598 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 2.6.19 onward and has been patched in 5.10.271, 5.15.222, 6.1.189 and others. CVE-2026-97598 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-2026-97598?
Yes. CVE-2026-97598 has been patched. Fixed versions include 5.10.271, 5.15.222, 6.1.189 and others. If you are running Linux kernel 2.6.19 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-97598 actively exploited?
No. CVE-2026-97598 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.