MFSA2026-58: Security Vulnerabilities fixed in Firefox ESR 140.12
Published Jun 16, 2026
·Updated
Security Vulnerabilities fixed in Firefox ESR 140.12
Affected Software
1 affected componentFixes available
Mozilla Firefox ESR<140.12
140.12
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 140.12 - Upgrade
Upgrade
Firefox ESRto a version that resolves this vulnerability.Fixed in 140.12
Event History
Jun 16, 2026
Advisory Published
via Mozilla·12:00 AM
Data Sourced
via Mozilla·12:00 AM
DescriptionSeverityAffected Software
Child vulnerabilities
Contains the following vulnerabilities.
- CVE-2026-12289
- CVE-2026-12290
- CVE-2026-12291
- CVE-2026-12292
- CVE-2026-12294
- CVE-2026-12295
- CVE-2026-12298
- CVE-2026-12296
- CVE-2026-12297
- CVE-2026-12299
- CVE-2026-12329
- CVE-2026-12302
- CVE-2026-12304
- CVE-2026-12305
- CVE-2026-12306
- CVE-2026-12307
- CVE-2026-12308
- CVE-2026-12309
- CVE-2026-12310
- CVE-2026-12311
- CVE-2026-12312
- CVE-2026-12313
- CVE-2026-12314
- CVE-2026-12315
- CVE-2026-12330
- CVE-2026-12324
- CVE-2026-12325
- CVE-2026-12327
- CVE-2026-12328
Frequently Asked Questions
1
What is the severity of MFSA2026-58?
The severity of MFSA2026-58 is categorized as high with a score of 7.
2
How do I fix MFSA2026-58?
To fix MFSA2026-58, update to Firefox ESR version 140.12 or later.
3
What vulnerabilities does MFSA2026-58 address?
MFSA2026-58 addresses multiple security vulnerabilities identified in previous versions of Firefox ESR.
4
When was MFSA2026-58 published?
MFSA2026-58 was published on June 16, 2026.
5
What software is affected by MFSA2026-58?
The affected software for MFSA2026-58 is Mozilla Firefox ESR.