CVE-2025-6436

HIGH

Firefox < 140.0 and Thunderbird < 140.0 - Memory Corruption

Title source: llm
STIX 2.1

Description

Memory safety bugs present in Firefox 139 and Thunderbird 139. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 140 and Thunderbird 140.

References (3)

Core 3

Scores

CVSS v3 8.1
EPSS 0.0051
EPSS Percentile 66.7%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact total

Details

CWE
CWE-119
Status published
Products (4)
mozilla/firefox < 140.0
Mozilla/Firefox 140
mozilla/thunderbird < 140.0
Mozilla/Thunderbird 140
Published Jun 24, 2025
Tracked Since Feb 18, 2026