CVE-2020-26956

Medium

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.

SeverityMedium
CVSS6.1
Exploit probability—
ProductMozilla Firefox
PublishedDec 9, 2020
First seenDec 9, 2020

How to fix

Update
  • mozilla firefox83.0 or later
  • mozilla firefox_esr78.5 or later
  • mozilla thunderbird78.5 or later

Affected products

ProductAffected versionsFixed in
mozilla firefoxv < 83.083.0
mozilla firefox_esrv < 78.578.5
mozilla thunderbirdv < 78.578.5

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