CVE-2026-100819
Received Received - Intake

XPCOM Boundary Condition Sandbox Escape in Firefox

Publication date: 2026-09-29

Last updated on: 2026-09-29

Assigner: Mozilla Corporation

Description
Sandbox escape due to incorrect boundary conditions in the XPCOM component. This vulnerability was fixed in Firefox ESR 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-09-29
Last Modified
2026-09-29
Generated
2026-09-29
AI Q&A
2026-09-29
EPSS Evaluated
N/A
NVD
CVE-2026-100819
EUVD
EUVD-2026-88798

Affected Vendors & Products

Showing 7 associated CPEs
Vendor Product Version / Range
mozilla firefox to 153.4 (inc)
mozilla firefox 157
mozilla firefox to 115.42 (inc)
mozilla firefox to 140.17 (inc)
mozilla firefox 153.4
mozilla firefox 115.42
mozilla firefox 140.17

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-UNKNOWN

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This vulnerability allows an attacker to escape the sandbox due to incorrect boundary conditions in the XPCOM component of Firefox. This means malicious code could run outside the restricted environment, potentially gaining higher system privileges.

Impact Analysis

If exploited, this vulnerability could allow an attacker to execute arbitrary code on your system, leading to data theft, malware installation, or unauthorized access. Users of affected Firefox versions are at risk until they update to the patched versions.

Mitigation Strategies

Update Firefox to a patched version: Firefox ESR 153.4, Firefox 157, Firefox ESR 115.42, or Firefox ESR 140.17 or later. Disable XPCOM components if not required.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-100819. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart