// For flags

CVE-2025-5266

firefox: thunderbird: Script element events leaked cross-origin resource status

Severity Score

6.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

Script elements loading cross-origin resources generated load and error events which leaked information enabling XS-Leaks attacks. This vulnerability affects Firefox < 139 and Firefox ESR < 128.11.

Script elements loading cross-origin resources generated load and error events which leaked information enabling XS-Leaks attacks. This vulnerability affects Firefox < 139, Firefox ESR < 128.11, Thunderbird < 139, and Thunderbird < 128.11.

A flaw was found in Firefox. The Mozilla Foundation's Security Advisory describes the following issue: Script elements loading cross-origin resources generate load and error events which can leak information enabling XS-Leaks attacks.

Multiple security issues have been found in the Mozilla Firefox web browser, which could potentially result in the execution of arbitrary code or cross-origin leaks. For the stable distribution (bookworm), these problems have been fixed in version 128.11.0esr-1~deb12u1.

*Credits: Jakub Szymsza
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2025-05-27 CVE Reserved
  • 2025-05-27 CVE Published
  • 2025-06-11 CVE Updated
  • 2025-08-03 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
  • CWE-829: Inclusion of Functionality from Untrusted Control Sphere
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Mozilla
Search vendor "Mozilla"
Firefox
Search vendor "Mozilla" for product "Firefox"
*-
Affected
Mozilla
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Firefox Esr
Search vendor "Mozilla" for product "Firefox Esr"
*-
Affected
Mozilla
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Thunderbird
Search vendor "Mozilla" for product "Thunderbird"
*-
Affected
Slackware
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Slackware Linux
Search vendor "Slackware" for product "Slackware Linux"
*-
Affected