# CVE-2021-47950: Advanced Guestbook 2.4.4 Persistent XSS via Smilies

> Authenticated attackers can inject persistent scripts via the smilies administration interface, leading to code execution when administrators view the page.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA: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:** 10 May 2026
- **Updated:** 15 Jul 2026
- **Also known as:** GHSA-4x8q-cwhj-47mg

## What is CVE-2021-47950?

CVE-2021-47950 is a medium-severity cross-site scripting vulnerability in Ampps Advanced Guestbook, published on 10 May 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Advanced Guestbook 2.4.4 contains a persistent cross-site scripting vulnerability in the smilies administration interface that allows authenticated attackers to inject malicious scripts by manipulating the s_emotion parameter. Attackers can submit POST requests to admin.php with JavaScript code in the s_emotion field, which executes when administrators view the smilies tab.

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

## Which versions are affected by CVE-2021-47950?


## How do I fix CVE-2021-47950?

No fix has been published for CVE-2021-47950 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-47950 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-47950 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-47950 and fix it if it is affected.

What it is: CVE-2021-47950 is a medium-severity cross-site scripting vulnerability in Ampps Advanced Guestbook, published on 10 May 2026. 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-2021-47950 exists.

Affected product: Ampps Advanced Guestbook. 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-2021-47950/ (Markdown: https://insights.sbomify.com/CVE-2021-47950/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47950
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47950
- OSV: https://osv.dev/vulnerability/CVE-2021-47950

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-47950/
Summaries are generated and may contain mistakes; the official description above is the record.