VULNERABILITY INTELLIGENCE

CVE-2026-84642

CVSS score7.5 HIGH
EPSS probability0.42%
CISA KEVNot currently listed
Published2026-09-01
Last modified2026-09-03
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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.

Weakness classification

  • 134c704f-9b21-4f2e-91b3-4a467353bcc0: CWE-1333

Primary references