CVE-2026-126132: Mozilla Thunderbird · Attachments could be replaced with local file content when forwarding
Affects Mozilla ThunderbirdSource CVE Database V5
Not known to be exploited · fixed in 153.7 : patch Mozilla Thunderbird soon.
Data as of 10 Nov 2026, 20:34 UTC
Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD
Thin evidence
One scorer or none- Patch
- Available – fixed in 153.7
Exploitation evidence
Disclosed: evidence found.
CVE published 10 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 10 Nov 2026.
What to do
AI-suggested
This vulnerability is fixed in Thunderbird 160. Users should update to Thunderbird 160 or later to remediate this issue. No additional mitigation actions are required once updated.
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.