# CVE-2026-96238: .NET Security Feature Bypass Vulnerability

> An origin validation error in .NET allows attackers to bypass security features over the network, requiring patches for affected versions.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 13 Oct 2026
- **Updated:** 29 Oct 2026
- **Also known as:** UBUNTU-CVE-2026-96238

## What is CVE-2026-96238?

CVE-2026-96238 is a medium-severity vulnerability in Microsoft .NET 10.0 runtime, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Origin validation error in .NET allows an unauthorized attacker to bypass a security feature over a network.

Weakness: CWE-346 (Origin Validation Error)

## Which versions are affected by CVE-2026-96238?


## How do I fix CVE-2026-96238?

Apply the vendor's patch.

## Is CVE-2026-96238 being exploited?

There is no known exploitation of CVE-2026-96238 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-96238 and fix it if it is affected.

What it is: CVE-2026-96238 is a medium-severity vulnerability in Microsoft .NET 10.0 runtime, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-96238 in the wild and no public exploit code.

Affected product: Microsoft .NET 10.0 runtime. 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-2026-96238/ (Markdown: https://insights.sbomify.com/CVE-2026-96238/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-96238
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-96238
- OSV: https://osv.dev/vulnerability/CVE-2026-96238

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-96238/
Summaries are generated and may contain mistakes; the official description above is the record.