CVEvulnerability

CVE-2026-84143

9.8 CRITICAL Published 2026-09-01 Modified 2026-09-03 Official page ↗
Status
Modified
Published
2026-09-01
Last modified
2026-09-03
Assigner
[email protected]
CVSS 3.1 ([email protected])
9.8 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 3.1 (134c704f-9b21-4f2e-91b3-4a467353bcc0)
9.8 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weaknesses
CWE-119, CWE-200

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.

Affected configurations

• mozilla firefox (< 140.15.0) • mozilla firefox (>= 141.0.0 < 153.2.0) • mozilla firefox (>= 154.0.0 < 155.0.0) • mozilla thunderbird (< 140.15.0) • mozilla thunderbird (>= 141.0 < 153.2.0) • mozilla thunderbird (>= 154.0 < 155.0)

Related

Weakness · CWE (2)

  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer weakness
  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor weakness

References