# CVE-2026-99122: vsock/vmci: validate packet source for connected sockets


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 28 Oct 2026
- **Updated:** 28 Oct 2026
- **Also known as:** AZL-111224, BELL-CVE-2026-99122, DEBIAN-CVE-2026-99122, GHSA-99x3-rpwc-xh78, UBUNTU-CVE-2026-99122

## What is CVE-2026-99122?

CVE-2026-99122 is a vulnerability in Linux, published on 28 Oct 2026. 

### Official description

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

vsock/vmci: validate packet source for connected sockets

vmci_transport_recv_stream_cb() looks up sockets first by the full source
and destination tuple, then by destination only in the bound table. The
fallback can select a non-listening socket without checking whether the
packet came from its stored peer.

This was reproduced with two VMCI contexts. A RST from the context not
stored in a TCP_SYN_SENT socket reset that socket after it was selected by
the destination-only lookup.

VMCI can process notification packets in bottom-half context when the
socket is not owned by user context, or defer packets to a workqueue. Use
vsock_check_source() after taking the socket lock in the bottom-half path,
and recheck after lock_sock() in the workqueue path. Listening sockets
continue to accept packets from any source.

Reply with a RST addressed from the received packet before dropping a
source that fails validation. This preserves the existing reset behavior
for bound non-listening and concurrently closed sockets without directing
the reset to a connected socket's stored peer.

## Which versions are affected by CVE-2026-99122?


## How do I fix CVE-2026-99122?

Upgrade to a fixed version.

## Is CVE-2026-99122 being exploited?

There is no known exploitation of CVE-2026-99122 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-99122 and fix it if it is affected.

What it is: CVE-2026-99122 is a vulnerability in Linux, published on 28 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-99122 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-2026-99122/ (Markdown: https://insights.sbomify.com/CVE-2026-99122/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-99122
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-99122
- OSV: https://osv.dev/vulnerability/CVE-2026-99122

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-99122/
Summaries are generated and may contain mistakes; the official description above is the record.