# CVE-2026-83947: Azure Event Grid Spoofing Vulnerability

> An authorized attacker can perform spoofing attacks against Azure Event Grid due to missing authorization checks.

- **Severity:** High 7.7 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N/E:U/RL:O/RC:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 8 Oct 2026
- **Updated:** 29 Oct 2026
- **Also known as:** GHSA-hf67-p98c-9g49

## What is CVE-2026-83947?

CVE-2026-83947 is a high-severity missing authorization vulnerability in Microsoft Azure Event Grid System, published on 8 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Missing authorization in Azure Event Grid allows an authorized attacker to perform spoofing over a network.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-83947?

It affects 1 product.


Products: Microsoft Azure Event Grid.

## How do I fix CVE-2026-83947?

No fix has been published for CVE-2026-83947 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-83947 being exploited?

There is no known exploitation of CVE-2026-83947 in the wild and no public exploit code.

## Other vulnerabilities in Microsoft Azure Event Grid System

- [CVE-2025-59273](https://insights.sbomify.com/CVE-2025-59273/): Azure Event Grid System Elevation of Privilege Vulnerability (high 7.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-83947 and fix it if it is affected.

What it is: CVE-2026-83947 is a high-severity missing authorization vulnerability in Microsoft Azure Event Grid System, published on 8 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-83947 in the wild and no public exploit code.

Affected product: Microsoft Azure Event Grid System. 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-2026-83947/ (Markdown: https://insights.sbomify.com/CVE-2026-83947/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-83947
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-83947
- OSV: https://osv.dev/vulnerability/CVE-2026-83947

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-83947/
Summaries are generated and may contain mistakes; the official description above is the record.