CVE-2026-74988

CRITICAL CVSS 3.1: 9.8 EPSS 0.35%
Updated Aug 24, 2026
Mozilla
Parameter Value
CVSS 9.8 (CRITICAL)
Affected Versions before 153.1.0
Fixed In 153.1.0
Type CWE-119 (Buffer Overflow)
Vendor Mozilla
Public PoC No

Internally found bugs present in Firefox ESR 153.0 and Firefox 153. 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 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service

CVSS Vector v3.1

Weakness Type (CWE)

Vulnerable Products 4

Configuration From (including) Up to (excluding)
Mozilla Firefox
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
153.1.0
Mozilla Firefox
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
153.1.0
Mozilla Thunderbird
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
153.1.0
Mozilla Thunderbird
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*
153.1.0