CVE-2026-118175

EUVD-2026-111352
When replying to, forwarding, or editing a crafted email message as new, Thunderbird could embed parts of a different message stored in the same folder into the message being composed, without showing a blocked content warning. If the user sent the message, the content of the other message was disclosed to the recipients. This vulnerability was fixed in Thunderbird 159 and Thunderbird 153.6.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
mozillaCNA
UNKNOWN
---
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources (CNA/ADP records, vendor advisories, Enginsight analysis).
VendorProductVersionSource
mozillathunderbird
𝑥
< 159
CNA
mozillathunderbird_esr
141.0.0 ≤
𝑥
< 153.6
CNA
Debian logo
Debian Releases
Debian Product
Codename
thunderbird
bookworm
vulnerable
bookworm (security)
vulnerable
forky
vulnerable
sid
vulnerable
trixie
vulnerable
trixie (security)
vulnerable
References
https://bugzilla.mozilla.org/show_bug.cgi?id=2081720
https://www.mozilla.org/security/advisories/mfsa2026-121/
https://www.mozilla.org/security/advisories/mfsa2026-122/