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
0.08% (37th percentile)

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  • Snyk IDSNYK-DEBIAN11-FIREFOXESR-1041093
  • published18 Nov 2020
  • disclosed9 Dec 2020

Introduced: 18 Nov 2020

CVE-2020-26951  (opens in a new tab)
CWE-79  (opens in a new tab)

How to fix?

Upgrade Debian:11 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:11 relevant fixed versions and status.

A parsing and event loading mismatch in Firefox's SVG code could have allowed load events to fire, even after sanitization. An attacker already capable of exploiting an XSS vulnerability in privileged internal pages could have used this attack to bypass our built-in sanitizer. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

CVSS Scores

version 3.1