6.1

CVE-2021-23980: mozilla bleach

Modified
AliasesMGASA-2021-0260GHSA-vv2x-vrpj-qqpqPYSEC-2021-865
Published 16-02-2023Last modified 19-03-2025
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Vulnerability summary

CVE-2021-23980 is a medium (CVSS 6.1) vulnerability in mozilla bleach. EPSS estimates a 0.48% chance of exploitation in the next 30 days, higher than 41.6% of scored vulnerabilities. 1 public exploit is recorded.

Priority
Routine

Not severe (CVSS 6.1, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
6.1/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.48%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits1reference

Advisory lineage

Upstream 0 · Downstream 5 · Related 5
OPENSUSE-SU-2021:0552-1OPENSUSE-SU-2021:0571-1OPENSUSE-SU-2024:14134-1OPENSUSE-SU-2026:11323-1RHSA-2021:0781USN-8077-1

Timeline

  1. 16-02-2023
    PublishedVulnerability first disclosed.
  2. 19-03-2025
    Last modifiedVulnerability information updated.

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.

CVSS metrics

7 scores · 6 sources · 2 versions

EPSS trend

Probability

0.48%

Chance of exploitation in the next 30 days

Percentile

42%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.48% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

1 found
  • referenceUnverified

    Exploit Reference (bugzilla.mozilla.org)

    Maturity: unknown

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, user interaction (CVSS vector). Other conditions: not stated in public data.

Mageia2 products
  • python-bleach< 3.1.4-1.1.mga7
  • python-bleach< 3.3.0-1.mga8
Mozilla2 products
Alpine1 product
  • py3-bleach< 3.3.0-r0
Debian1 product
  • python-bleach< 3.1.2-0+deb10u2 | < 2.0-1+deb9u1 | < 3.2.1-2.1
PyPI1 product
  • bleach< 79b7a3c5e56a09d1d323a5006afa59b56162eb13 | < 3.3.0
Ubuntu1 product
  • python-bleach< 1.4.2-1ubuntu0.1~esm1 | < 2.1.2-1ubuntu0.1~esm1 | < 3.1.1-1ubuntu0.1~esm1

6 vendors · 8 products

References

21 links
Show all 21 references