Access Control Bypass Affecting Firefox-ESR package, versions [,115.37)[116.0,140.12)


Severity

Recommended
0.0
medium
0
10

CVSS assessment by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
0.36% (29th percentile)

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  • Snyk IDSNYK-UNMANAGED-FIREFOXESR-17391637
  • published21 Jun 2026
  • disclosed16 Jun 2026
  • creditUnknown

Introduced: 16 Jun 2026

CVE-2026-12294  (opens in a new tab)
CWE-284  (opens in a new tab)

How to fix?

Upgrade Firefox-ESR to version 115.37, 140.12 or higher.

Overview

Affected versions of this package are vulnerable to Access Control Bypass via the Workers process. An attacker can execute code outside of the intended sandbox by leveraging crafted web content.

CVSS Base Scores

version 4.0
version 3.1