CVE-2021-43540

—

CVSS 3.1

6.5 medium

EPSS

<1%p56

Published

Dec 8, 2021 (Dec 8, 2021)

Modified

Jun 17, 2026

Description

WebExtensions with the correct permissions were able to create and install ServiceWorkers for third-party websites that would not have been uninstalled with the extension. This vulnerability affects Firefox < 95.

Vendors: mozilla
Products: firefox
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

NVD CVE.org GitHub PoCs EPSS (0.9%)

In the news0 stories

No ingested article mentions this CVE yet.