CVE-2026-118175
highWhen 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 th…
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2081720 security@mozilla.org
- https://www.mozilla.org/security/advisories/mfsa2026-121/ security@mozilla.org
- https://www.mozilla.org/security/advisories/mfsa2026-122/ security@mozilla.org

