# CVE-2026-97618: io_uring/net: don't overconsume buffers when using MSG_TRUNC

> A local attacker can cause buffer overconsumption in io_uring network operations, potentially leading to denial of service or information disclosure.

- **Severity:** Not scored
- **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:** 25 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-97618, DEBIAN-CVE-2026-97618, GHSA-qrrw-9q98-7ph9, UBUNTU-CVE-2026-97618

## What is CVE-2026-97618?

CVE-2026-97618 is a vulnerability in Linux, published on 25 Sep 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:

io_uring/net: don't overconsume buffers when using MSG_TRUNC

When a recv/recvmsg is issued with MSG_TRUNC and the incoming packet is
larger than the provided buffer, the net layer returns the full length
of the packet rather than the number of bytes actually copied into the
buffer.  As a result, io_uring advances more of the provided buffer ring
than was actually filled.  Use the actual filled region size to consume
the buffer, but still return the full size to preserve MSG_TRUNC
semantics.

Take care with multishot, because that seems to already truncate the
consumption based on the available payload size.

This was reported in https://github.com/axboe/liburing/issues/1619.

[axboe: fold in size_t unsigned fix]

## Which versions are affected by CVE-2026-97618?


## How do I fix CVE-2026-97618?

Apply the vendor's patch.

## Is CVE-2026-97618 being exploited?

There is no known exploitation of CVE-2026-97618 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-97618 and fix it if it is affected.

What it is: CVE-2026-97618 is a vulnerability in Linux, published on 25 Sep 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-2026-97618 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-2026-97618/ (Markdown: https://insights.sbomify.com/CVE-2026-97618/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-97618
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-97618
- OSV: https://osv.dev/vulnerability/CVE-2026-97618

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-97618/
Summaries are generated and may contain mistakes; the official description above is the record.