# CVE-2018-20986: Cross-site scripting in n/a

> Authors can inject malicious scripts via the Advanced Custom Fields plugin, potentially leading to code execution in the context of other users.

- **Severity:** Medium 5.4 (`CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 22 Aug 2019
- **Updated:** 5 Aug 2024
- **Also known as:** CVE-2018-17557, GHSA-3ggh-h43h-cwc6

## What is CVE-2018-20986?

CVE-2018-20986 is a medium-severity cross-site scripting vulnerability in n/a, published on 22 Aug 2019. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

The advanced-custom-fields (aka Elliot Condon Advanced Custom Fields) plugin before 5.7.8 for WordPress has XSS by authors.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2018-20986?

It affects 1 product.


Products: Advancedcustomfields Advanced Custom Fields.

## How do I fix CVE-2018-20986?

No fix has been published for CVE-2018-20986 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-20986 being exploited?

There is no known exploitation of CVE-2018-20986 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2023-1196](https://insights.sbomify.com/CVE-2023-1196/): Advanced Custom Fields - Contributor+ PHP Object Injection (high 8.8)
- [CVE-2022-2594](https://insights.sbomify.com/CVE-2022-2594/): Advanced Custom Fields 5.0-5.12.2 - Unauthenticated File Upload (high 8.8)
- [CVE-2024-4565](https://insights.sbomify.com/CVE-2024-4565/): Advanced Custom Fields < 6.3 - Contributor+ Custom Field Access (high 7.5)
- [CVE-2021-20865](https://insights.sbomify.com/CVE-2021-20865/): Missing authorization in Advanced Custom Fields and Advanced Custom Fields Pro (high 7.5)
- [CVE-2023-30777](https://insights.sbomify.com/CVE-2023-30777/): WordPress Advanced Custom Fields / Advanced Custom Fields PRO plugins <= 6.1.5 vulnerable to Cross Site Scripting (XSS) (high 7.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-20986 and fix it if it is affected.

What it is: CVE-2018-20986 is a medium-severity cross-site scripting vulnerability in n/a, published on 22 Aug 2019. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2018-20986 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-2018-20986/ (Markdown: https://insights.sbomify.com/CVE-2018-20986/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-20986
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-20986
- OSV: https://osv.dev/vulnerability/CVE-2018-20986

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-20986/
Summaries are generated and may contain mistakes; the official description above is the record.