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/…
Published: 2025-06-24 · CVSS: 4.3 · CVSS 3.1
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 128.12, Thunderbird 140, and Thunderbird 128.12.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7