CVE-2026-126132 Attachments could be replaced with local file content when forwarding
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-126132?
CVE-2026-126132 is a vulnerability in Mozilla Thunderbird, published on 10 Nov 2026.
Official description
When a message was forwarded inline, edited as new, or had an attachment dragged into a compose window, a specially crafted link attachment (a .desktop file on Linux, or a .url or .lnk file on Windows) was replaced with the content of the file or URL it pointed to when the message was saved or sent. This could disclose local files, or content from the user's network, to the message recipients or to the mail provider. This bug only affects Thunderbird on Linux and Windows. Other operating systems are unaffected. This vulnerability was fixed in Thunderbird 160 and Thunderbird 153.7.
Which versions are affected by CVE-2026-126132?
How do I fix CVE-2026-126132?
Upgrade to a fixed version.
Is CVE-2026-126132 being exploited?
There is no known exploitation of CVE-2026-126132 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-126132, GHSA-m77w-xfm2-m3w5, UBUNTU-CVE-2026-126132.