CVE-2026-2776

CRITICAL

Firefox < 115.33.0 and 140.8-148.0 - Sandbox Escape via Telemetry Boundary Condition Flaw

Title source: llm
STIX 2.1

Description

Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

References (6)

Core 6

Scores

CVSS v3 10.0
EPSS 0.0003
EPSS Percentile 8.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact total

Details

CWE
CWE-119
Status published
Products (9)
mozilla/firefox < 115.33.0
mozilla/firefox < 148.0
Mozilla/Firefox 115.33 - 115.*
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