# CVE-2026-68289: tipc: fix integer overflow in tipc_recvmsg() and tipc_recvstream()

> An integer overflow in the Linux kernel TIPC module allows local attackers to trigger a kernel panic via crafted io_uring operations.

- **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:** 10 Aug 2026
- **Updated:** 3 Oct 2026
- **Also known as:** AZL-95199, BELL-CVE-2026-68289, DEBIAN-CVE-2026-68289, GHSA-cxm4-x446-vhq4, UBUNTU-CVE-2026-68289

## What is CVE-2026-68289?

CVE-2026-68289 is a vulnerability in Linux, published on 10 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: fix integer overflow in tipc_recvmsg() and tipc_recvstream()

In tipc_recvmsg(), the copy length is computed as:

  copy = min_t(int, dlen - offset, buflen);

buflen is size_t but min_t(int, ...) casts it to int. When buflen
exceeds INT_MAX (e.g. 0xFFFFFFFF via io_uring provided buffers), it
wraps negative, wins the comparison, and the negative copy length
propagates to simple_copy_to_iter() where int-to-size_t promotion
makes it SIZE_MAX, triggering a WARN_ON. tipc_recvstream() has the
same pattern.

  Kernel panic - not syncing: kernel: panic_on_warn set ...
  RIP: 0010:simple_copy_to_iter+0x9e/0xd0 (net/core/datagram.c:521)
  Call Trace:
   __skb_datagram_iter+0x123/0x8b0 (net/core/datagram.c:402)
   skb_copy_datagram_iter+0x77/0x1a0 (net/core/datagram.c:534)
   tipc_recvmsg+0x3d7/0xe80 (net/tipc/socket.c:1934)
   io_recvmsg+0x47e/0xda0

Fix by changing min_t(int, ...) to min_t(size_t, ...) in both
functions. The result is always <= (dlen - offset), which is bounded
by TIPC maximum message size (0x1ffff bytes), so the implicit
narrowing on assignment to int copy is always safe.

## Which versions are affected by CVE-2026-68289?


## How do I fix CVE-2026-68289?

Apply the vendor's patch.

## Is CVE-2026-68289 being exploited?

There is no known exploitation of CVE-2026-68289 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68289 and fix it if it is affected.

What it is: CVE-2026-68289 is a vulnerability in Linux, published on 10 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-2026-68289 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-2026-68289/ (Markdown: https://insights.sbomify.com/CVE-2026-68289/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68289
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68289
- OSV: https://osv.dev/vulnerability/CVE-2026-68289

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68289/
Summaries are generated and may contain mistakes; the official description above is the record.