# CVE-2026-46137: mptcp: pm: ADD_ADDR rtx: fix potential data-race

> A data race in the Linux kernel MPTCP path manager timer callback can lead to undefined behavior due to missing socket locking.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 28 May 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-88983, BELL-CVE-2026-46137, DEBIAN-CVE-2026-46137, GHSA-cmf4-rm73-rfhx, ROOT-OS-DEBIAN-11-CVE-2026-46137, ROOT-OS-DEBIAN-12-CVE-2026-46137, ROOT-OS-DEBIAN-13-CVE-2026-46137, ROOT-OS-UBUNTU-2204-CVE-2026-46137, ROOT-OS-UBUNTU-2404-CVE-2026-46137, UBUNTU-CVE-2026-46137

## What is CVE-2026-46137?

CVE-2026-46137 is a critical vulnerability in Linux kernel, published on 28 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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

mptcp: pm: ADD_ADDR rtx: fix potential data-race

This mptcp_pm_add_timer() helper is executed as a timer callback in
softirq context. To avoid any data races, the socket lock needs to be
held with bh_lock_sock().

If the socket is in use, retry again soon after, similar to what is done
with the keepalive timer.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2026-46137?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-46137?

Apply the vendor's patch.

## Is CVE-2026-46137 being exploited?

There is no known exploitation of CVE-2026-46137 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-46137 and fix it if it is affected.

What it is: CVE-2026-46137 is a critical vulnerability in Linux kernel, published on 28 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-46137 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-46137/ (Markdown: https://insights.sbomify.com/CVE-2026-46137/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46137
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46137
- OSV: https://osv.dev/vulnerability/CVE-2026-46137

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46137/
Summaries are generated and may contain mistakes; the official description above is the record.