Information Disclosure and Sandbox Escape in Firefox by Mozilla
CVE-2026-12311

4.7MEDIUM

Key Information:

Vendor

Mozilla
Status
Firefox
Thunderbird
Vendor
CVE Published:
16 June 2026

What is CVE-2026-12311?

This vulnerability in the Security: Process Sandboxing component of Firefox allows attackers to bypass sandbox protections, potentially leading to unauthorized access to sensitive information. The issue has been resolved in Firefox version 152 and Firefox ESR version 140.12, enhancing the security and integrity of user data.

Affected Version(s)

Firefox 140.12

Firefox 152

Thunderbird 140.12

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2040177
https://www.mozilla.org/security/advisories/mfsa2026-57/
https://www.mozilla.org/security/advisories/mfsa2026-58/

CVSS V3.1

Score:
4.7
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Yaqoub Aldurayhim
.