# CVE-2026-31642: rxrpc: Fix call removal to use RCU safe deletion

> A flaw in the Linux kernel's rxrpc module can cause an infinite loop when reading /proc/net/rxrpc/calls, leading to a denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 24 Apr 2026
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-83756, BELL-CVE-2026-31642, DEBIAN-CVE-2026-31642, GHSA-q4rh-73g2-jf4j, ROOT-OS-DEBIAN-11-CVE-2026-31642, ROOT-OS-DEBIAN-12-CVE-2026-31642, ROOT-OS-DEBIAN-13-CVE-2026-31642, ROOT-OS-UBUNTU-2204-CVE-2026-31642, ROOT-OS-UBUNTU-2404-CVE-2026-31642, UBUNTU-CVE-2026-31642

## What is CVE-2026-31642?

CVE-2026-31642 is a medium-severity denial of service vulnerability in Linux kernel, published on 24 Apr 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:

rxrpc: Fix call removal to use RCU safe deletion

Fix rxrpc call removal from the rxnet->calls list to use list_del_rcu()
rather than list_del_init() to prevent stuffing up reading
/proc/net/rxrpc/calls from potentially getting into an infinite loop.

This, however, means that list_empty() no longer works on an entry that's
been deleted from the list, making it harder to detect prior deletion.  Fix
this by:

Firstly, make rxrpc_destroy_all_calls() only dump the first ten calls that
are unexpectedly still on the list.  Limiting the number of steps means
there's no need to call cond_resched() or to remove calls from the list
here, thereby eliminating the need for rxrpc_put_call() to check for that.

rxrpc_put_call() can then be fixed to unconditionally delete the call from
the list as it is the only place that the deletion occurs.

Weakness: CWE-835 (Loop with Unreachable Exit Condition)

## Which versions are affected by CVE-2026-31642?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-31642?

Apply the vendor's patch.

## Is CVE-2026-31642 being exploited?

There is no known exploitation of CVE-2026-31642 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-2026-31642 and fix it if it is affected.

What it is: CVE-2026-31642 is a medium-severity denial of service vulnerability in Linux kernel, published on 24 Apr 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-2026-31642 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-2026-31642/ (Markdown: https://insights.sbomify.com/CVE-2026-31642/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31642
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31642
- OSV: https://osv.dev/vulnerability/CVE-2026-31642

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-31642/
Summaries are generated and may contain mistakes; the official description above is the record.