CVEvulnerability
CVE-2026-84642
7.5 HIGH
Official page ↗
- Status
- Analyzed
- Published
- 2026-09-01
- Last modified
- 2026-09-03
- Assigner
- [email protected]
- CVSS 3.1 (134c704f-9b21-4f2e-91b3-4a467353bcc0)
- 7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- Weaknesses
- CWE-1333
Description
The values of the mail.allowed_attachment_hostnames advanced config setting were used in a regular expression without escaping. For some possible valid hostnames, this could allow certain unintended hostnames to also match and serve remote attachments. This vulnerability was fixed in Thunderbird 155 and Thunderbird 153.2.
Affected configurations
• mozilla thunderbird (< 153.2.0)
• mozilla thunderbird (>= 154.0 < 155.0)
Related
Weakness · CWE (1)
- CWE-1333 Inefficient Regular Expression Complexity weakness
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2060462 Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2026-86/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-88/ Vendor Advisory