# CVE-2021-47835: Freeter 1.2.1 - Persistent Cross-Site Scripting

> Attackers can inject malicious scripts via widget titles or files in Freeter, potentially leading to remote code execution when victims interact with the application.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/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:** 16 Jan 2026
- **Updated:** 16 Jan 2026
- **Also known as:** GHSA-xfw8-xm28-h6fx

## What is CVE-2021-47835?

CVE-2021-47835 is a medium-severity cross-site scripting vulnerability in Freeter, published on 16 Jan 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

Freeter 1.2.1 contains a persistent cross-site scripting vulnerability that allows attackers to store malicious payloads in custom widget titles and files. Attackers can craft malicious files with embedded scripts that execute when victims interact with the application, potentially enabling remote code execution.

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

## Which versions are affected by CVE-2021-47835?


## How do I fix CVE-2021-47835?

No fix has been published for CVE-2021-47835 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-47835 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-47835 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-47835 and fix it if it is affected.

What it is: CVE-2021-47835 is a medium-severity cross-site scripting vulnerability in Freeter, published on 16 Jan 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-2021-47835 exists.

Affected product: Freeter. 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-2021-47835/ (Markdown: https://insights.sbomify.com/CVE-2021-47835/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47835
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47835
- OSV: https://osv.dev/vulnerability/CVE-2021-47835

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-47835/
Summaries are generated and may contain mistakes; the official description above is the record.