# CVE-2020-27418: Use after free in n/a

> Attackers can obtain sensitive information via a use-after-free flaw in the Linux kernel's vgacon_invert_region function.

- **Severity:** Medium 4.4 (`CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 22 Aug 2023
- **Updated:** 9 Jul 2026
- **Also known as:** DEBIAN-CVE-2020-27418, GHSA-v9gh-f54x-54f5, UBUNTU-CVE-2020-27418

## What is CVE-2020-27418?

CVE-2020-27418 is a medium-severity use after free vulnerability in n/a, published on 22 Aug 2023. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A Use After Free vulnerability in Fedora Linux kernel 5.9.0-rc9 allows attackers to obatin sensitive information via vgacon_invert_region() function.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2020-27418?

It affects 1 product.


Products: Fedoraproject Fedora Linux Kernel.

## How do I fix CVE-2020-27418?

Apply the vendor's patch.

## Is CVE-2020-27418 being exploited?

There is no known exploitation of CVE-2020-27418 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-27418 and fix it if it is affected.

What it is: CVE-2020-27418 is a medium-severity use after free vulnerability in n/a, published on 22 Aug 2023. 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-2020-27418 in the wild and no public exploit code.

Affected product: n/a. 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-2020-27418/ (Markdown: https://insights.sbomify.com/CVE-2020-27418/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-27418
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-27418
- OSV: https://osv.dev/vulnerability/CVE-2020-27418

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-27418/
Summaries are generated and may contain mistakes; the official description above is the record.