# CVE-2021-23980: python-bleach: A mutation XSS affects users calling bleach.clean with all of: svg or math in the allowed tags p or br in allowed tag...

CVE-2021-23980 is fixed in 2 products on 1 platform, first by python-bleach 2.1.2-1ubuntu0.1~esm1, released February 16, 2023. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2021-23980
- Priority: Routine
- CVSS: 6.1 (medium)
- EPSS: 0.0048
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Feb 16, 2023

## Description

A mutation XSS affects users calling bleach.clean with all of: svg or math in the allowed tags p or br in allowed tags style, title, noscript, script, textarea, noframes, iframe, or xmp in allowed tags the keyword argument strip_comments=False Note: none of the above tags are in the default allowed tags and strip_comments defaults to True.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | python-bleach Debian 12.15 (bookworm) | 3.2.1-2.1 | [DEBIAN-CVE-2021-23980](https://patchblox.com/security/data/fix/linux/debian-cve-2021-23980.md) | Feb 16, 2023 |
| Linux | python-bleach Debian 13.5 (trixie) | 3.2.1-2.1 | [DEBIAN-CVE-2021-23980](https://patchblox.com/security/data/fix/linux/debian-cve-2021-23980.md) | Feb 16, 2023 |
| Linux | python-bleach Debian 14 | 3.2.1-2.1 | [DEBIAN-CVE-2021-23980](https://patchblox.com/security/data/fix/linux/debian-cve-2021-23980.md) | Feb 16, 2023 |
| Linux | python-bleach Ubuntu 18.04.6 LTS (bionic) | 2.1.2-1ubuntu0.1~esm1 | [python-bleach 2.1.2-1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python-bleach-2.1.2-1ubuntu0.1-esm1.md) | Feb 16, 2023 |
| Linux | python3-bleach Ubuntu 18.04.6 LTS (bionic) | 2.1.2-1ubuntu0.1~esm1 | [python3-bleach 2.1.2-1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python3-bleach-2.1.2-1ubuntu0.1-esm1.md) | Feb 16, 2023 |
| Linux | python3-bleach Ubuntu 20.04 LTS (focal) | 3.1.1-1ubuntu0.1~esm1 | [python3-bleach 3.1.1-1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-python3-bleach-3.1.1-1ubuntu0.1-esm1.md) | Feb 16, 2023 |

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Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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