Medium 5.4Published Jun 16, 2026

CVE-2026-12298Memory safety bug fixed in Thunderbird 152

Updated under an hour ago (Oct 28, 2026, 1:23 AM ET)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

Memory safety bug fixed in Thunderbird 152. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.

CVSS: 5.4 MEDIUM (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Weakness (CWE): CWE-125, CWE-787, CWE-416, CWE-843
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: mozilla
NVD analysis: Modified
Record last updated: Oct 21, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Mozilla Firefox mozilla:firefox (from the name)	140.12 builds before 140.* not affected; from 152 not affected	CNA record
Mozilla Thunderbird mozilla:thunderbird (from the name)	140.12 builds before 140.* not affected; from 152 not affected	CNA record
Red Hat Red Hat Enterprise Linux 10 redhat:enterprise_linux	from 0:140.12.0-1.el10_2 not affected	CISA ADP
Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support redhat:enterprise_linux_eus	from 0:140.12.0-1.el10_0 not affected	CISA ADP
Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support redhat:rhel_els	from 0:140.12.0-1.el7_9 not affected	CISA ADP
Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support redhat:rhel_aus	from 0:140.12.0-1.el8_4 not affected	CISA ADP
Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On redhat:rhel_eus_long_life	from 0:140.12.0-1.el8_4 not affected	CISA ADP
Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service redhat:rhel_tus	from 0:140.12.0-1.el8_8 not affected	CISA ADP
Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions redhat:rhel_e4s	from 0:140.12.0-1.el8_8 not affected	CISA ADP
Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support redhat:rhel_eus	from 0:140.12.0-1.el9_6 not affected	CISA ADP
1–10 of 12

References

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2041981	permissions-required
https://www.mozilla.org/security/advisories/mfsa2026-57/	vendor-advisory
https://www.mozilla.org/security/advisories/mfsa2026-58/	vendor-advisory
https://www.mozilla.org/security/advisories/mfsa2026-60/	vendor-advisory
https://www.mozilla.org/security/advisories/mfsa2026-61/	vendor-advisory
https://access.redhat.com/errata/RHSA-2026:27717
https://access.redhat.com/errata/RHSA-2026:27733
https://access.redhat.com/errata/RHSA-2026:27734
https://access.redhat.com/errata/RHSA-2026:29940
https://access.redhat.com/errata/RHSA-2026:30846
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The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.