Improper Restriction of Rendered UI Layers or Frames Affecting firefox-esr package, versions <135-r0


Severity

Recommended
0.0
medium
0
10

Snyk's Security Team recommends NVD's CVSS assessment. Learn more

Threat Intelligence

EPSS
0.41% (34th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-CHAINGUARDLATEST-FIREFOXESR-17765098
  • published1 Jul 2026
  • disclosed4 Feb 2025

Introduced: 4 Feb 2025

CVE-2025-1018  (opens in a new tab)
CWE-1021  (opens in a new tab)

How to fix?

Upgrade Chainguard firefox-esr to version 135-r0 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 Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

The fullscreen notification is prematurely hidden when fullscreen is re-requested quickly by the user. This could have been leveraged to perform a potential spoofing attack. This vulnerability was fixed in Firefox 135 and Thunderbird 135.

CVSS Base Scores

version 3.1