CVE-2026-0891

HIGH

Firefox and Thunderbird < 147 - Memory Corruption

Title source: llm
STIX 2.1

Description

Memory safety bugs present in Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146. 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 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.

References (31)

Core 31
Core References

Scores

CVSS v3 8.1
EPSS 0.0041
EPSS Percentile 33.4%
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 no
Technical Impact total

Details

CWE
CWE-119
Status published
Products (8)
mozilla/firefox < 140.7.0
mozilla/firefox < 147.0
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