VulnerabilityModified
CVE-2020-26956
In some cases, removing HTML elements during sanitization would keep existing SVG event handlers and therefore lead to XSS.
MEDIUM 6.1EPSS 1.23%
Does this matter?
Lower severity and a low EPSS score (1.23%). Track it; it rarely justifies an emergency change on its own.
Description
In some cases, removing HTML elements during sanitization would keep existing SVG event handlers and therefore lead to XSS. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.
- CVSS 3.1
- 6.1 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- EPSS
- 1.23% probability · 67th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-79
- Affected
- mozilla/firefox · mozilla/firefox esr · mozilla/thunderbird
- Source
- security@mozilla.org
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1666300Issue Tracking, Permissions Required, Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2020-50/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2020-51/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2020-52/Vendor Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1666300Issue Tracking, Permissions Required, Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2020-50/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2020-51/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2020-52/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.