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CVE-2020-6816In Mozilla Bleach before 3.12, a mutation XSS in bleach.clean when RCDATA and either svg or math tags are whitelisted and the keyword…
- 6.1MediumCVSS base score
- 1.3%Exploitation in 30 daysEPSS · top 28% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By mozilla
- 2 months later
· 2 months later
Published
- 4 years later
· 4 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Medium6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
- EPSS (exploitation in 30 days)
- 1.3% · top 28% of all CVEs (14 Nov 2026)
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.1.
Affected products
Mozilla Bleach
- affected <=3.11
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- PyPIbleachGHSA-m6xf-fq7q-8743 (opens in a new tab)
References
References4
- https://github.com/mozilla/bleach/security/advisories/GHSA-m6xf-fq7q-8743 (opens in a new tab)x_refsource_MISCx_transferred
- https://www.checkmarx.com/blog/vulnerabilities-discovered-in-mozilla-bleach (opens in a new tab)x_refsource_MISCx_transferred
- FEDORA-2020-e0f35d634c (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- https://advisory.checkmarx.net/advisory/CX-2020-4277 (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2020-0055 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-m6xf-fq7q-8743 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2020-6816)Record last updated .