Cross-site Scripting (XSS) Affecting firefox-esr package, versions <78.5.0esr-1


Severity

Recommended
0.0
medium
0
10

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Threat Intelligence

EPSS
0.1% (43rd percentile)

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  • Snyk IDSNYK-DEBIAN12-FIREFOXESR-1546089
  • published18 Nov 2020
  • disclosed9 Dec 2020

Introduced: 18 Nov 2020

CVE-2020-26956  (opens in a new tab)
CWE-79  (opens in a new tab)

How to fix?

Upgrade Debian:12 firefox-esr to version 78.5.0esr-1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream firefox-esr package and not the firefox-esr package as distributed by Debian. See How to fix? for Debian:12 relevant fixed versions and status.

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 Scores

version 3.1