# CVE-2023-39777: Cross-site scripting in n/a

> Attackers can execute arbitrary scripts in the vBulletin Admin Control Panel via a login URL parameter, potentially compromising administrator accounts.

- **Severity:** Medium 5.4 (`CVSS:3.1/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:** 16 Sep 2023
- **Updated:** 25 Sep 2024
- **Also known as:** GHSA-8mfq-mqv3-25m4

## What is CVE-2023-39777?

CVE-2023-39777 is a medium-severity cross-site scripting vulnerability in Vbulletin Vbulletin, published on 16 Sep 2023. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

A cross-site scripting (XSS) vulnerability in the Admin Control Panel of vBulletin 5.7.5 and 6.0.0 allows attackers to execute arbitrary web scripts or HTML via the /login.php?do=login url parameter.

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

## Which versions are affected by CVE-2023-39777?

It affects 1 product.


Products: Vbulletin Vbulletin.

## How do I fix CVE-2023-39777?

No fix has been published for CVE-2023-39777 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-39777 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-39777 exists.

## Other vulnerabilities in Vbulletin Vbulletin

- [CVE-2020-17496](https://insights.sbomify.com/CVE-2020-17496/): vBulletin PHP Module Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2019-16759](https://insights.sbomify.com/CVE-2019-16759/): vBulletin PHP Module Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2025-48827](https://insights.sbomify.com/CVE-2025-48827/): vBulletin 5.0.0 through 5.7.5 and 6.0.0 through 6.0.3 allows unauthenticated users to invoke protected API controllers' methods when running (critical 10.0)
- [CVE-2023-25135](https://insights.sbomify.com/CVE-2023-25135/): Deserialization in n/a (critical 9.8)
- [CVE-2020-7373](https://insights.sbomify.com/CVE-2020-7373/): Code injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-39777 and fix it if it is affected.

What it is: CVE-2023-39777 is a medium-severity cross-site scripting vulnerability in Vbulletin Vbulletin, published on 16 Sep 2023. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-39777 exists.

Affected product: Vbulletin Vbulletin. 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-2023-39777/ (Markdown: https://insights.sbomify.com/CVE-2023-39777/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-39777
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-39777
- OSV: https://osv.dev/vulnerability/CVE-2023-39777

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-39777/
Summaries are generated and may contain mistakes; the official description above is the record.