# CVE-2026-90114: net: bridge: Reject descending VLAN tunnel ranges

> An integer overflow in Linux kernel bridge VLAN tunnel range checks can cause unpredictable return values and potential denial of service.

- **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:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-102212, BELL-CVE-2026-90114, DEBIAN-CVE-2026-90114, GHSA-3m56-382v-r3qq, UBUNTU-CVE-2026-90114

## What is CVE-2026-90114?

CVE-2026-90114 is a vulnerability in Linux, published on 17 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:

net: bridge: Reject descending VLAN tunnel ranges

A pair of descending VLAN and tunnel IDs can pass the tunnel range span
check. The VLAN subtraction produces a negative int, which is converted
to unsigned when compared with the u32 tunnel ID subtraction. It can
therefore equal the wrapped tunnel ID delta.

The range loop then performs no iterations. Since the batched
notification handling added a post-loop error check, this leaves err
uninitialized and makes the request's return value unpredictable.

Reject descending VLAN ranges before comparing the spans. Valid
ascending and single-entry ranges remain unchanged, while malformed
descending ranges consistently return -EINVAL.

This issue was found by a static analysis checker and confirmed by
manual source review.

## Which versions are affected by CVE-2026-90114?


## How do I fix CVE-2026-90114?

Apply the vendor's patch.

## Is CVE-2026-90114 being exploited?

There is no known exploitation of CVE-2026-90114 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90114 and fix it if it is affected.

What it is: CVE-2026-90114 is a vulnerability in Linux, published on 17 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-2026-90114 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-2026-90114/ (Markdown: https://insights.sbomify.com/CVE-2026-90114/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90114
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90114
- OSV: https://osv.dev/vulnerability/CVE-2026-90114

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90114/
Summaries are generated and may contain mistakes; the official description above is the record.