CVE-2026-100801: Privilege escalation in the DLL Services component

Published Sep 29, 2026

Updated

Privilege escalation in the DLL Services component. This vulnerability was fixed in Firefox ESR 153.4, Firefox 157, and Firefox ESR 140.17.

Affected Software

3 affected componentsFixes available

Mozilla Firefox ESR<140.17

140.17

Mozilla Firefox<157

157

Mozilla Firefox ESR<153.4

153.4

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 140.17
Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 157
Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 153.4
Upgrade
Upgrade Firefox ESR to a version that resolves this vulnerability.
Fixed in 153.4
Upgrade
Upgrade Firefox to a version that resolves this vulnerability.
Fixed in 157
Upgrade
Upgrade Firefox ESR to a version that resolves this vulnerability.
Fixed in 140.17

Sep 29, 2026

CVE Published

via Mozilla·12:00 AM

Data Sourced

via Mozilla·12:00 AM

DescriptionSeverityAffected Software

Updated

via Mozilla·12:00 AM

Affected Software

CVE Published

via MITRE·12:36 PM

Data Sourced

via MITRE·12:36 PM

Description

Data Sourced

via NVD·01:17 PM

DescriptionSeverityWeakness

This vulnerability appears in the following advisories.

Found alongside the following vulnerabilities.