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.
CVE-2021-23980
This medium-severity CVE scores 6.1 under NVD CVSS v3. EPSS exploit probability: 0.5%, top 34% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- Lower severity and no public exploit yet
A fix is available — apply it.
- CVSS v3
- 6.1
- EG Score
- 6.1(medium)
- EPSS
- 38.3%
- KEV
- Not listed
Published
February 16, 2023
Last Modified
March 19, 2025
References (4)
- security@mozillahttps://bugzilla.mozilla.org/show_bug.cgi?id=CVE-2021-23980
- security@mozillahttps://github.com/mozilla/bleach/security/advisories/GHSA-vv2x-vrpj-qqpq
- af854a3a-2127-422b-91ae-364da2661108https://bugzilla.mozilla.org/show_bug.cgi?id=CVE-2021-23980
- af854a3a-2127-422b-91ae-364da2661108https://github.com/mozilla/bleach/security/advisories/GHSA-vv2x-vrpj-qqpq
Patch Availability(2)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| ubuntu | python3-bleach (3.1.1-1ubuntu0.1~esm1) @ focal | 2026-05-25 | ubuntu |
| redhat | python-pulp-ansible-1:0.5.6-1.el8pc | 2021-03-09 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(1 across 1 ecosystem)
PyPI(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| bleach | 0.1 ... 3.2.3 (50 versions) | 3.3.0 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
All Vendor Advisories
(3)
Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.
- Microsoft MSRCCVE-2021-239802025-09-03
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.
- Red HatRHSA-2021:0781MODERATE2021-02-02
RHSA-2021:0781 — Moderate
- UbuntuUSN-8077-1MEDIUM
Bleach vulnerabilities
Data Freshness Timeline
(refreshed 9× in last 7d / 48× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-12 05:44 UTCEPSS rescore
- 2026-07-12 05:44 UTCEPSS rescore
- 2026-07-11 08:25 UTCEPSS rescore
- 2026-07-09 19:07 UTCEPSS rescore
- 2026-07-08 15:12 UTCEPSS rescore
- 2026-07-07 13:43 UTCEPSS rescore
- 2026-07-06 16:25 UTCEPSS rescore
- 2026-07-06 02:21 UTCEPSS rescore
- 2026-07-06 02:21 UTCEPSS rescore
- 2026-07-05 02:28 UTCEPSS rescore
- 2026-07-05 02:28 UTCEPSS rescore
- 2026-07-04 06:29 UTCEPSS rescore
- 2026-07-04 06:29 UTCEPSS rescore
- 2026-07-02 16:57 UTCEPSS rescore
- 2026-07-01 15:03 UTCEPSS rescore
- 2026-06-30 23:20 UTCEPSS rescore
- 2026-06-30 23:20 UTCEPSS rescore
- 2026-06-29 14:04 UTCEPSS rescore
- 2026-06-29 14:04 UTCEPSS rescore
- 2026-06-28 14:05 UTCEPSS rescore
- 2026-06-28 05:22 UTCOSV refresh
- 2026-06-28 04:54 UTCEPSS rescore
- 2026-06-28 04:54 UTCEPSS rescore
- 2026-06-27 03:06 UTCEPSS rescore
- 2026-06-27 03:06 UTCEPSS rescore
Show 60 moreShow fewer
- 2026-06-25 13:48 UTCEPSS rescore
- 2026-06-25 13:48 UTCEPSS rescore
- 2026-06-24 14:03 UTCEPSS rescore
- 2026-06-24 14:03 UTCEPSS rescore
- 2026-06-23 21:31 UTCEPSS rescore
- 2026-06-23 21:31 UTCEPSS rescore
- 2026-06-22 14:24 UTCEPSS rescore
- 2026-06-22 14:23 UTCEPSS rescore
- 2026-06-21 14:54 UTCEPSS rescore
- 2026-06-21 14:54 UTCEPSS rescore
- 2026-06-21 01:58 UTCEPSS rescore
- 2026-06-21 01:57 UTCEPSS rescore
- 2026-06-19 19:24 UTCEPSS rescore
- 2026-06-19 19:24 UTCEPSS rescore
- 2026-06-18 17:51 UTCEPSS rescore
- 2026-06-18 17:51 UTCEPSS rescore
- 2026-06-17 17:51 UTCEPSS rescore
- 2026-06-16 17:50 UTCEPSS rescore
- 2026-06-15 17:46 UTCEPSS rescore
- 2026-06-14 23:15 UTCEPSS rescore
- 2026-06-13 22:58 UTCEPSS rescore
- 2026-06-12 23:10 UTCEPSS rescore
- 2026-06-12 23:10 UTCEPSS rescore
- 2026-06-11 13:58 UTCEPSS rescore
- 2026-06-10 22:16 UTCEPSS rescore
- 2026-06-10 22:16 UTCEPSS rescore
- 2026-06-10 15:47 UTCOSV refresh
- 2026-06-10 13:20 UTCEPSS rescore
- 2026-06-08 14:15 UTCEPSS rescore
- 2026-06-08 14:15 UTCEPSS rescore
- 2026-06-07 15:23 UTCEPSS rescore
- 2026-06-07 15:23 UTCEPSS rescore
- 2026-06-06 13:46 UTCEPSS rescore
- 2026-06-06 13:46 UTCEPSS rescore
- 2026-06-06 13:46 UTCEPSS rescore
- 2026-06-05 22:45 UTCEPSS rescore
- 2026-06-05 22:45 UTCEPSS rescore
- 2026-06-05 06:09 UTCEPSS rescore
- 2026-06-05 06:09 UTCEPSS rescore
- 2026-06-05 06:08 UTCEPSS rescore
- 2026-06-04 13:10 UTCEPSS rescore
- 2026-06-02 20:11 UTCEPSS rescore
- 2026-06-02 20:11 UTCEPSS rescore
- 2026-06-01 13:50 UTCEPSS rescore
- 2026-06-01 13:50 UTCEPSS rescore
- 2026-05-31 22:29 UTCEPSS rescore
- 2026-05-31 22:29 UTCEPSS rescore
- 2026-05-31 00:15 UTCEPSS rescore
- 2026-05-31 00:15 UTCEPSS rescore
- 2026-05-29 13:42 UTCEPSS rescore
- 2026-05-28 13:43 UTCEPSS rescore
- 2026-05-28 13:43 UTCEPSS rescore
- 2026-05-27 13:39 UTCEPSS rescore
- 2026-05-26 13:42 UTCEPSS rescore
- 2026-05-26 13:42 UTCEPSS rescore
- 2026-05-26 07:17 UTCEPSS rescore
- 2026-05-26 07:17 UTCEPSS rescore
- 2026-05-25 06:31 UTCEG score recompute
- 2026-05-25 06:31 UTCVendor advisory
- 2026-05-24 16:49 UTCEPSS rescore
Related CVEs(same vendor + same CWE)
Same vendor
10 shownmsrc · redhat
Frequently asked(5)
What is CVE-2021-23980?
When was CVE-2021-23980 disclosed?
Is CVE-2021-23980 actively exploited?
What is the CVSS score of CVE-2021-23980?
How do I remediate CVE-2021-23980?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-23980
Is Your Infrastructure Affected by CVE-2021-23980?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.