CVE-2025-6425 The WebCompat WebExtension shipped with Firefox exposed a persistent UUID

An attacker who enumerated resources from the WebCompat extension could have obtained a persistent UUID that identified the browser, and persisted between containers and normal/private browsing mode, but not profiles. This vulnerability was fixed in Firefox 140, Firefox ESR 115.25, Firefox ESR...

CVE-2025-6425

The WebCompat extension in Mozilla Firefox and Mozilla Thunderbird is vulnerable to an information disclosure flaw. An attacker who enumerates resources from the extension can obtain a persistent UUID that identifies the browser. This UUID persists between containers and normal/private browsing m...

CVE-2025-6425: Exposure of Sensitive Information to an Unauthorized Actor

An attacker who enumerated resources from the WebCompat extension could have obtained a persistent UUID that identified the browser, and persisted between containers and normal/private browsing mode, but not profiles. This vulnerability was fixed in Firefox 140, Firefox ESR 115.25, Firefox ESR...

Mozilla -- persistent UUID that identifies browser

[email protected] reports: An attacker who enumerated resources from the WebCompat extension could have obtained a persistent UUID that identified the browser, and persisted between containers and normal/private browsing mode, but not profiles. This vulnerability affects Firefox 140, Firefox E...