CVE-2026-118174
Displaying a message could load an attacker-chosen URL through an OpenPGP key attachment
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.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| Thunderbird Mozilla |
≥ 153.6; ≤ 153.* (unaffected, rpm) ≥ 159; ≤ * (unaffected, rpm) |
CNA: mozilla |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 3.1 / 6.5 medium |
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N | ADP: CISA-ADP |
| 3.1 / 6.5 medium |
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N | NVD: 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2080910CNA: mozilla
- https://www.mozilla.org/security/advisories/mfsa2026-121/CNA: mozilla
- https://www.mozilla.org/security/advisories/mfsa2026-122/CNA: mozilla
- https://bugzilla.mozilla.org/show_bug.cgi?id=2080910[email protected]
- https://www.mozilla.org/security/advisories/mfsa2026-121/[email protected]
- https://www.mozilla.org/security/advisories/mfsa2026-122/[email protected]
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