CVE-2025-5266: Script element events leaked cross-origin resource status
Script elements loading cross-origin resources generated load and error events which leaked information enabling XS-Leaks attacks.
Affected Software
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 139 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 128.11 - Upgrade
Upgrade
Firefoxto a version that resolves this vulnerability.Fixed in 139 - Upgrade
Upgrade
Firefox ESRto a version that resolves this vulnerability.Fixed in 128.11 - Upgrade
Upgrade
Thunderbirdto a version that resolves this vulnerability.Fixed in 139 - Upgrade
Upgrade
Thunderbird ESRto a version that resolves this vulnerability.Fixed in 128.11
Event History
Parent advisories
This vulnerability appears in the following advisories.
Peer vulnerabilities
Found alongside the following vulnerabilities.
Frequently Asked Questions
What is the severity of CVE-2025-5266?
The severity of CVE-2025-5266 is classified as moderate due to its potential to enable XS-Leaks attacks.
How do I fix CVE-2025-5266?
To fix CVE-2025-5266, update Mozilla Firefox to version 139 or Firefox ESR to version 128.11.
Which versions of Firefox are affected by CVE-2025-5266?
CVE-2025-5266 affects versions of Firefox prior to 139 and Firefox ESR prior to 128.11.
What kind of attacks can CVE-2025-5266 enable?
CVE-2025-5266 can enable XS-Leaks attacks by leaking information through load and error events from cross-origin resources.
Is user interaction required for CVE-2025-5266 to be exploited?
No, CVE-2025-5266 can be exploited without user interaction, highlighting its significance.