REDHAT-BUG-2517823: High severity Mozilla Firefox ESR vulnerability
Published Aug 18, 2026
·Updated
Internally found bugs present in Firefox ESR 140.13, Firefox ESR 153.0 and Firefox 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1.
Affected Software
2 affected components
Mozilla Firefox ESR=140.13, =140.14
Mozilla Firefox=153.0, =153, =153.1, =154
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 154 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 140.14 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 153.1
Event History
Aug 18, 2026
Data Sourced
via Red Hat·12:47 PM
DescriptionSeverityAffected Software