CVE-2026-63858: netfilter: nf_tables: add hook transactions for device deletions

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-19 · updated 2026-10-26
Weakness: CWE-362

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: add hook transactions for device deletions Restore the flag that indicates that the hook is going away, ie. NFT_HOOK_REMOVE, but add a new transaction object to track deletion of hooks without altering the basechain/flowtable hook_list during the preparation phase. The existing approach that moves the hook from the basechain/flowtable hook_list to transaction hook_list breaks netlink dump path readers of this RCU-protected list. It should be possible use an array for nft_trans_hook to store the deleted hooks to compact the representation but I am not expecting many hook object, specially now that wildcard support for devices is in place. Note that the nft_trans_chain_hooks() list contains a list of struct nft_trans_hook objects for DELCHAIN and DELFLOWTABLE commands, while this list stores struct nft_hook objects for NEWCHAIN and NEWFLOWTABLE. Note that new commands can be updated to use nft_trans_hook for consistency. This patch also adapts the event notification path to deal with the list of hook transactions.

Affected products

Linux kernel: from 5.10.122 before 5.11; from 5.15.47 before 5.16; from 5.17.15 before 5.18; from 5.18.4 before 5.19; from 5.19.1 before 6.18.57; from 6.19 before 7.0.10 — fixed in 5.11, 5.16, 5.18, 5.19, 6.18.57, 7.0.10
Linux kernel: from 5.10.122 before 5.11; from 5.15.47 before 5.16; from 5.17.15 before 5.18; from 5.18.4 before 5.19; 5.19 — fixed in 5.11, 5.16, 5.18, 5.19, 7.1

How to fix

Upgrade to a fixed version: Linux kernel 5.11, 5.16, 5.18, 5.19; Linux kernel 5.11, 5.16, 5.18, 5.19. Check the vendor advisory for mitigations.

References

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