CVE-2026-0877

HIGH

Firefox <147- Thunderbird <140.7 - Mitigation Bypass

Title source: llm
STIX 2.1

Description

Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 147, Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.

Scores

CVSS v3 8.1
EPSS 0.0002
EPSS Percentile 6.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-693
Status published
Products (9)
mozilla/firefox < 115.32.0
mozilla/firefox < 147.0
Mozilla/Firefox 115.32 - 115.*
Mozilla/Firefox 140.7 - 140.*
Mozilla/Firefox 147
mozilla/thunderbird < 140.7.0
mozilla/thunderbird < 147.0
Mozilla/Thunderbird 140.7 - 140.*
Mozilla/Thunderbird 147
Published Jan 13, 2026
Tracked Since Feb 18, 2026