CVE-2026-118174
A sender could mark the attachment as an external attachment pointing to an arbitrary URL, which Thunderbird then loaded without any user interaction, bypassing remote content blocking.
Does this matter?
Not yet scored. NVD analysis is pending; check back once CVSS and EPSS values are published.
Description
When a message containing an OpenPGP key attachment was displayed, Thunderbird automatically loaded the attachment's content to offer importing the key. A sender could mark the attachment as an external attachment pointing to an arbitrary URL, which Thunderbird then loaded without any user interaction, bypassing remote content blocking. On Windows, a URL pointing to an attacker-controlled network share could leak the user's NTLM credentials. The NTLM credential leak only affects Thunderbird on Windows. On other operating systems, the issue allowed a remote request that bypassed remote content blocking. This vulnerability was fixed in Thunderbird 159 and Thunderbird 153.6.
- CVSS
- Not yet scored
- EPSS
- No score yet
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Source
- security@mozilla.org
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.