CVE-2026-84639

EUVD-2026-69708
Triggering an error condition in certain MIME bodies would cause uninitialized memory to be used. This vulnerability was fixed in Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
mozillaCNA
9.1 CRITICAL
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 23.7%
Affected Products (NVD)
VendorProductVersion
mozillathunderbird
𝑥
< 140.15.0
mozillathunderbird
141.0 ≤
𝑥
< 153.2.0
𝑥
= Vulnerable software versions
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
mozillathunderbird
154.0 ≤
𝑥
< 155.0
CNA
mozillathunderbird_esr
𝑥
< 140.15.0
CNA
mozillathunderbird_esr
141.0 ≤
𝑥
< 153.2.0
CNA
Debian logo
Debian Releases
Debian Product
Codename
thunderbird
bookworm
vulnerable
bookworm (security)
1:140.17.0esr-1~deb12u1
fixed
forky
1:153.4.0esr-1
fixed
sid
1:153.4.0esr-1
fixed
trixie
vulnerable
trixie (security)
1:140.17.0esr-1~deb13u1
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
thunderbird
jammy
needs-triage
noble
needs-triage
resolute
needs-triage
openSUSE logo
openSUSE / SLES Releases
openSUSE Product
Release
MozillaThunderbird
suse enterprise desktop 15 SP7
153.2.0-150400.13.3.1
fixed
suse enterprise sap 15 SP7
153.2.0-150400.13.3.1
fixed
suse enterprise server 15 SP7
153.2.0-150400.13.3.1
fixed
suse enterprise workstation 15 SP7
153.2.0-150400.13.3.1
fixed
MozillaThunderbird-translations-common
suse enterprise desktop 15 SP7
153.2.0-150400.13.3.1
fixed
suse enterprise sap 15 SP7
153.2.0-150400.13.3.1
fixed
suse enterprise server 15 SP7
153.2.0-150400.13.3.1
fixed
suse enterprise workstation 15 SP7
153.2.0-150400.13.3.1
fixed
MozillaThunderbird-translations-other
suse enterprise desktop 15 SP7
153.2.0-150400.13.3.1
fixed
suse enterprise sap 15 SP7
153.2.0-150400.13.3.1
fixed
suse enterprise server 15 SP7
153.2.0-150400.13.3.1
fixed
suse enterprise workstation 15 SP7
153.2.0-150400.13.3.1
fixed
Red Hat logo
Red Hat Enterprise Linux Releases
Red Hat Product
Release
thunderbird
RHEL 9
0:140.16.0-1.el9_8
fixed
Amazon Linux logo
Amazon Linux Releases
Amazon Package
Release
thunderbird
Amazon Linux 2
0:140.16.0-1.amzn2.0.1
fixed