# CVE-2020-0638: Microsoft Update Notification Manager Privilege Escalation

> An attacker with local access can exploit file handling flaws in the Update Notification Manager to elevate privileges on Windows systems.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Yes, since 23 May 2022 (CISA KEV), used in ransomware
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Jan 2020
- **Updated:** 12 Aug 2026
- **Also known as:** GHSA-53p9-m4mr-wp8x

## What is CVE-2020-0638?

CVE-2020-0638 is a high-severity vulnerability in Microsoft Windows 10 1809, published on 14 Jan 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An elevation of privilege vulnerability exists in the way the Update Notification Manager handles files.To exploit this vulnerability, an attacker would first have to gain execution on the victim system, aka 'Update Notification Manager Elevation of Privilege Vulnerability'.

Weakness: CWE-59 (Improper Link Resolution Before File Access)

## Which versions are affected by CVE-2020-0638?

It affects 9 products.


Products: Microsoft Windows 10 1709, Microsoft Windows 10 1803, Microsoft Windows 10 1809, Microsoft Windows 10 1903, Microsoft Windows 10 1909, Microsoft Windows Server 1803, Microsoft Windows Server 1903, Microsoft Windows Server 1909, Microsoft Windows Server 2019.

## How do I fix CVE-2020-0638?

No fix has been published for CVE-2020-0638 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 13 Jun 2022.

## Is CVE-2020-0638 being exploited?

Yes. Attackers have exploited CVE-2020-0638 in the wild since at least 23 May 2022, including in ransomware campaigns.

## Other vulnerabilities in Microsoft Windows 10 1809

- [CVE-2019-1385](https://insights.sbomify.com/CVE-2019-1385/): Microsoft Windows AppX Deployment Extensions Privilege Escalation (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-0638 and fix it if it is affected.

What it is: CVE-2020-0638 is a high-severity vulnerability in Microsoft Windows 10 1809, published on 14 Jan 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2020-0638 in the wild since at least 23 May 2022, including in ransomware campaigns.

Affected product: Microsoft Windows 10 1809. 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-2020-0638/ (Markdown: https://insights.sbomify.com/CVE-2020-0638/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-0638
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-0638
- OSV: https://osv.dev/vulnerability/CVE-2020-0638

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-0638/
Summaries are generated and may contain mistakes; the official description above is the record.