CVE-2026-2766

CRITICAL

Firefox < 148 and Firefox ESR < 140.8 - Use-After-Free in JavaScript Engine JIT

Title source: llm
STIX 2.1

Description

Use-after-free in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

References (33)

Core 33
Core References

Scores

CVSS v3 9.8
EPSS 0.0047
EPSS Percentile 37.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/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-416
Status published
Products (8)
mozilla/firefox < 140.8.0
mozilla/firefox < 148.0
Mozilla/Firefox 140.8 - 140.*
Mozilla/Firefox 148
mozilla/thunderbird < 140.8.0
mozilla/thunderbird < 148.0
Mozilla/Thunderbird 140.8 - 140.*
Mozilla/Thunderbird 148
Published Feb 24, 2026
Tracked Since Feb 24, 2026