# CVE-2026-74283: tipc: require net admin for TIPCv2 netlink mutators

> Unprivileged local users can modify TIPC network state and keys due to missing admin permission checks in TIPCv2 netlink mutators.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** BELL-CVE-2026-74283, DEBIAN-CVE-2026-74283, GHSA-5jpm-p694-hhf9, UBUNTU-CVE-2026-74283

## What is CVE-2026-74283?

CVE-2026-74283 is a high-severity missing authorization vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

tipc: require net admin for TIPCv2 netlink mutators

TIPCv2 registers mutating generic-netlink operations without admin
permission flags. Generic netlink only checks CAP_NET_ADMIN when an
operation sets GENL_ADMIN_PERM or GENL_UNS_ADMIN_PERM, so a local
unprivileged process can currently change TIPC state through commands
such as TIPC_NL_NET_SET, TIPC_NL_KEY_SET, TIPC_NL_KEY_FLUSH, and
bearer enable/disable.

The legacy TIPC netlink API already checks netlink_net_capable(...,
CAP_NET_ADMIN) for administrative commands. Give the TIPCv2 mutators
the equivalent generic-netlink gate. Use GENL_UNS_ADMIN_PERM, which
maps to the same namespace-aware CAP_NET_ADMIN check that
netlink_net_capable() performs, so the behaviour matches the legacy
path and keeps working for CAP_NET_ADMIN holders in a non-initial user
namespace (containers).

A QEMU/KASAN repro run as uid/gid 65534 with zero effective
capabilities previously succeeded in changing the network id and node
identity, setting and flushing key material, and enabling/disabling a
UDP bearer. With this patch applied the same operations fail with
-EPERM.

## Which versions are affected by CVE-2026-74283?


## How do I fix CVE-2026-74283?

Apply the vendor's patch.

## Is CVE-2026-74283 being exploited?

There is no known exploitation of CVE-2026-74283 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74283 and fix it if it is affected.

What it is: CVE-2026-74283 is a high-severity missing authorization vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-74283 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-74283/ (Markdown: https://insights.sbomify.com/CVE-2026-74283/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74283
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74283
- OSV: https://osv.dev/vulnerability/CVE-2026-74283

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74283/
Summaries are generated and may contain mistakes; the official description above is the record.