CVE-2020-6816
MEDIUM6.1EPSS 0.42%Bleach vulnerable to mutation XSS via whitelisted math or svg and raw tag
Published: 3/24/2020Modified: 4/28/2026
Description
In Mozilla Bleach before 3.12, a mutation XSS in bleach.clean when RCDATA and either svg or math tags are whitelisted and the keyword argument strip=False.
Affected packages (4)
- Debian/python-bleachfrom 0, < 3.1.3-1
- Debian/python-bleachfrom 0, < 3.1.2-0+deb10u1
- PyPI/bleachfrom 0, < 3.1.2
- PyPI/bleachfrom 0, < 3.1.2
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N |
| osv | CVSS 3.1 | MEDIUM6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
References (10)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2020-6816
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2020-6816
- PATCHhttps://github.com/mozilla/bleach
- WEBhttps://advisory.checkmarx.net/advisory/CX-2020-4277
- WEBhttps://github.com/mozilla/bleach/releases/tag/v3.1.2
- WEBhttps://github.com/mozilla/bleach/security/advisories/GHSA-m6xf-fq7q-8743
- WEBhttps://github.com/pypa/advisory-database/tree/main/vulns/bleach/PYSEC-2020-28.yaml
- WEBhttps://lists.fedoraproject.org/archives/list/[email protected]/message/EDQU2SZLZMSSACCBUBJ6NOSRNNBDYFW5
- WEBhttps://lists.fedoraproject.org/archives/list/[email protected]/message/EDQU2SZLZMSSACCBUBJ6NOSRNNBDYFW5/
- WEBhttps://www.checkmarx.com/blog/vulnerabilities-discovered-in-mozilla-bleach