CVE-2026-8401 | Sandbox escape in the Profile Backup component. This vulnera… | CVSS 9.8 CRITICAL

Description

Sandbox escape in the Profile Backup component. This vulnerability was fixed in Firefox 150.0.3, Firefox ESR 115.36, Firefox ESR 140.11, and Thunderbird 140.11.

Metadata

CVE ID: CVE-2026-8401
State: PUBLISHED
Assigner: mozilla
Reserved: 2026-05-12 14:19 UTC
Published: 2026-05-12 14:24 UTC
Last updated: 2026-07-15 02:48 UTC
Primary CWE: CWE-693
CWE-693 Protection Mechanism Failure
Vendor / Product: Mozilla / Firefox
Sources: cve.org · NVD

Severity & Metrics

9.8 CRITICAL CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

SSVC — CISA Coordinator

Exploitation: none
Automatable: yes
Tech. Impact: total

Affected products (2)

Vendor	Product	Platform	Versions
Mozilla	Firefox	—	115.36 ≤ 115., 140.11 ≤ 140., 150.0.3 ≤ *
Mozilla	Thunderbird	—	140.11 ≤ *

Weakness (CWE)

CWE	Source	Description
CWE-653	adp	Improper Isolation or Compartmentalization
CWE-693	adp	CWE-693 Protection Mechanism Failure

CVSS scores (2)

Score	Severity	Version	Source	Vector
9.8	CRITICAL	3.1	adp	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5	HIGH	3.1	adp	CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

References (5)