VULNERABILITY INTELLIGENCE

CVE-2026-84143

CVSS score9.8 CRITICAL
EPSS probability0.38%
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:H/A:H

Description

Internally found bugs present in Thunderbird 154, Thunderbird ESR 153.1 and Thunderbird ESR 140.14. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 155, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.

Weakness classification

  • nvd@nist.gov: CWE-119
  • 134c704f-9b21-4f2e-91b3-4a467353bcc0: CWE-200

Primary references