CVE-2026-72254
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_fib: reject fib expression on the netdev egress hook A fib expression in a netdev egress base chain dereferences nft_in(pkt), NULL on the transmit path, causing a NULL pointer dereference at eval. nft_fib_validate() masks the hook with NF_INET_* values, but netdev hook numbers are a separate enum that aliases them (NF_NETDEV_EGRESS == NF_INET_LOCAL_IN), so an egress chain passes validation and then faults. Add nft_fib_netdev_validate() that limits each result/flag to the netdev hook where the device it reads exists: the input-device cases (OIF, OIFNAME, ADDRTYPE with F_IIF) to ingress, the output-device case (ADDRTYPE with F_OIF) to egress, ADDRTYPE with no device flag to both. Also restrict nft_fib_validate() to NFPROTO_IPV4/IPV6/INET so its NF_INET_* masks are not applied to another family's hooks.
Affected versions
Linux kernel versions
5.16
and later are affected. Fixed in
6.6.148,
6.12.101,
6.18.42,
7.1.5,
7.2-rc2
and their respective stable series.
References
5 totalFrequently asked questions
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What is CVE-2026-72254?
CVE-2026-72254 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 5.16 onward and has been patched in 6.6.148, 6.12.101, 6.18.42 and others. CVE-2026-72254 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-2026-72254?
Yes. CVE-2026-72254 has been patched. Fixed versions include 6.6.148, 6.12.101, 6.18.42 and others. If you are running Linux kernel 5.16 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-72254 actively exploited?
No. CVE-2026-72254 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.