CVE-2026-12327: Memory safety bugs fixed in Firefox ESR 140.12, Thunderbird ESR 140.12, Firefox 152 and Thunderbird 152
Memory safety bugs present in Firefox ESR 140.11, Thunderbird ESR 140.11, Firefox 151 and Thunderbird 151. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code.
Affected Software
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 to a fixed release to a version that resolves this vulnerability.
Fixed in 152
Event History
Parent advisories
This vulnerability appears in the following advisories.
Peer vulnerabilities
Found alongside 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
- CVE-2026-12293
- CVE-2026-12300
- CVE-2026-12301
- CVE-2026-12303
- CVE-2026-12316
- CVE-2026-12317
- CVE-2026-12318
- CVE-2026-12319
- CVE-2026-12320
- CVE-2026-12321
- CVE-2026-12322
- CVE-2026-12323
- CVE-2026-12326
Frequently Asked Questions
What is the severity of CVE-2026-12327?
CVE-2026-12327 has a high severity rating of 8.1 in the CVSS 3.1 system.
How do I fix CVE-2026-12327?
To fix CVE-2026-12327, you should update to the latest versions of Firefox ESR 140.12, Thunderbird ESR 140.12, Firefox 152, or Thunderbird 152.
What are the potential risks associated with CVE-2026-12327?
The risks associated with CVE-2026-12327 include potential memory corruption leading to arbitrary code execution.
Which software is affected by CVE-2026-12327?
CVE-2026-12327 affects Mozilla Firefox, Mozilla Thunderbird, and their Extended Support Releases (ESR) 140.11 and 151.
What types of vulnerabilities does CVE-2026-12327 involve?
CVE-2026-12327 involves memory safety bugs identified as buffer overflow vulnerabilities.