CVE-2026-12312: Memory safety bug fixed in Thunderbird 152
Memory safety bug fixed in Firefox 152. This vulnerability was fixed in Firefox 152 and Firefox ESR 140.12.
Other sources
Memory safety bug fixed in Firefox 152. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.
— MITRE
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 - Upgrade
Upgrade
Mozilla Firefoxto a version that resolves this vulnerability.Fixed in 152 - Upgrade
Upgrade
Firefox ESRto a version that resolves this vulnerability.Fixed in 140.12 - Upgrade
Upgrade
Mozilla Thunderbirdto a version that resolves this vulnerability.Fixed in 152 - Upgrade
Upgrade
Thunderbird ESRto a version that resolves this vulnerability.Fixed in 140.12
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-2026-12312?
CVE-2026-12312 has a high severity rating of 7.5 according to CVSS 3.1.
How do I fix CVE-2026-12312?
To fix CVE-2026-12312, update to Thunderbird 152 or the latest version of Firefox.
What types of software are affected by CVE-2026-12312?
CVE-2026-12312 affects Mozilla Thunderbird and Mozilla Firefox, including Firefox ESR.
What is the nature of the vulnerability described in CVE-2026-12312?
CVE-2026-12312 is a memory safety bug that can lead to buffer overflow issues.
When was CVE-2026-12312 published?
CVE-2026-12312 was published on June 16, 2026.