CVE-2026-118175
High
Description
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.
SeverityHigh
CVSS7.5
Exploit probability—
ProductThunderbird
PublishedOct 27, 2026
First seenOct 27, 2026
Weakness typeCWE-200Sensitive information exposure
How to fix
Update
- Thunderbird159, 153.6 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| Thunderbird | No range specified | 159, 153.6 |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
In the Intelligence 360 plan
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.