CVE-2021-23980
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
02 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
03 Exploitation and scoring
- Exploitation
- Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.
- SSVC decision
- ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 0.48% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 41.3% of scored records. A rank, not a probability.
- NVD base score
- 6.1 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- NVD analysis status
- Modified. NVD last modified this record on 2026-06-17.
- Red Hat severity
- Moderate. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2023-02-16 00:00Z3 YR AGO
- Last updated
- 2025-03-19 15:18Z1 YR AGO
- Reserved
- 2021-01-13
- Assigning CNA
- mozilla
- Record state
- PUBLISHED
- Severity
- Medium (CVSS 6.1)
- CNA CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- Weaknesses
- CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')Base
- Data version
- 5.1
- Document digest
- c480afade3b11a43b7cad9c671a43b2c244a6c617a77b5b4f8473c268d6c977e
05 Affected products
06 References
07 Fixed in
Debian 12
- python-bleach Fixed in 3.2.1-2.1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- python-bleach Fixed in 3.2.1-2.1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- python-bleach Fixed in 3.2.1-2.1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 16.04 LTS
- python-bleach Fixed in 1.4.2-1ubuntu0.1~esm1Available with Ubuntu Pro: https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 18.04 LTS
- python-bleach Fixed in 2.1.2-1ubuntu0.1~esm1Available with Ubuntu Pro: https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 20.04 LTS
- python-bleach Fixed in 3.1.1-1ubuntu0.1~esm1Available with Ubuntu Pro: https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.