CVE-2026-6754

Severity CVSS v4.0:

Pending analysis

Type:

CWE-416 Use After Free

Publication date:

21/04/2026

Last modified:

22/04/2026

Description

Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS v3.1 Severity and Metrics:

Base Score: 7.50 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): None
Availability (A): High

Base Score 3.x

7.50

Severity 3.x

HIGH

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:a:mozilla:firefox:::::esr:::*		115.35.0 (excluding)
cpe:2.3:a:mozilla:firefox:::::-:::*		150.0 (excluding)
cpe:2.3:a:mozilla:firefox:::::esr:::*	140.0 (including)	140.10.0 (excluding)
cpe:2.3:a:mozilla:thunderbird:::::esr:::*		140.10.0 (excluding)

To consult the complete list of CPE names with products and versions, see this page

CVE-2026-6754

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools