CVE-2026-12329

Memory safety bug fixed in Thunderbird ESR 140.12

Published Jun 16, 2026 CVSS 3.1 · 5.3 Medium EPSS < 1% KEV · Not listed
Description
Memory safety bug fixed in Thunderbird ESR 140.12. This vulnerability was fixed in Firefox ESR 140.12 and Thunderbird 140.12.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4635-1 firefox-esr security update
Debian DLA Debian DLA DLA-4636-1 thunderbird security update
Debian DSA Debian DSA DSA-6350-1 firefox-esr security update
Debian DSA Debian DSA DSA-6351-1 thunderbird security update
References
Link Providers
https://access.redhat.com/errata/RHSA-2026:27717 cve-icon
https://access.redhat.com/errata/RHSA-2026:27733 cve-icon
https://access.redhat.com/errata/RHSA-2026:27734 cve-icon
https://access.redhat.com/errata/RHSA-2026:29940 cve-icon
https://access.redhat.com/errata/RHSA-2026:30846 cve-icon
https://access.redhat.com/errata/RHSA-2026:33445 cve-icon
https://access.redhat.com/errata/RHSA-2026:36100 cve-icon
https://access.redhat.com/errata/RHSA-2026:36101 cve-icon
https://access.redhat.com/errata/RHSA-2026:36102 cve-icon
https://access.redhat.com/errata/RHSA-2026:36103 cve-icon
https://access.redhat.com/errata/RHSA-2026:37210 cve-icon
https://access.redhat.com/errata/RHSA-2026:37391 cve-icon
https://access.redhat.com/errata/RHSA-2026:38506 cve-icon
https://access.redhat.com/errata/RHSA-2026:38750 cve-icon
https://access.redhat.com/errata/RHSA-2026:38751 cve-icon
https://access.redhat.com/errata/RHSA-2026:38753 cve-icon
https://access.redhat.com/errata/RHSA-2026:39011 cve-icon
https://access.redhat.com/errata/RHSA-2026:39141 cve-icon
https://access.redhat.com/errata/RHSA-2026:39142 cve-icon
https://access.redhat.com/errata/RHSA-2026:39428 cve-icon
https://access.redhat.com/errata/RHSA-2026:39706 cve-icon
https://access.redhat.com/security/cve/CVE-2026-12329 cve-icon
https://bugzilla.mozilla.org/show_bug.cgi?id=2044738 cve-icon cve-icon
https://bugzilla.redhat.com/show_bug.cgi?id=2489214 cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-12329 cve-icon
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12329.json cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-12329 cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-58/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-58/#CVE-2026-12329 cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-61/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-61/#CVE-2026-12329 cve-icon
History
Type Values Removed Values Added
First Time appeared Mozilla thunderbird
CPEs cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*
Vendors & Products Mozilla thunderbird
Type Values Removed Values Added
Description Memory safety bug fixed in Firefox ESR 140.12. This vulnerability was fixed in Firefox ESR 140.12. Memory safety bug fixed in Thunderbird ESR 140.12. This vulnerability was fixed in Firefox ESR 140.12 and Thunderbird 140.12.
Title Memory safety bug fixed in Firefox ESR 140.12 Memory safety bug fixed in Thunderbird ESR 140.12
References
Type Values Removed Values Added
Weaknesses CWE-119
CWE-416
CWE-476
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Mozilla
Mozilla firefox
Vendors & Products Mozilla
Mozilla firefox
Type Values Removed Values Added
Description Memory safety bug fixed in Firefox ESR 140.12. This vulnerability was fixed in Firefox ESR 140.12.
Title Memory safety bug fixed in Firefox ESR 140.12
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mozilla
Published
Updated
Jul 15, 2026, 11:48 AM
Reserved
Jun 15, 2026, 3:08 PM
Status
Modified
Published
Jun 16, 2026, 1:16 PM
Modified
Oct 25, 2026, 11:10 PM
Severity
Important
Public date
Jun 16, 2026, 11:53 AM