Sandbox escape in Firefox Process Sandboxing

Successful exploitation allows an attacker to escape the browser sandbox. In practical terms, this can let code that is initially confined to a restricted browser process access resources or capabilities outside the intended sandbox boundary. The broader advisory context states Mozilla patched multiple flaws that could be chained, and specifically notes that sandbox escape vulnerabilities can be combined with browser memory corruption or code execution bugs to compromise the underlying system. Depending on the exploit chain and the privileges of the affected process or user, impact may include privilege escalation, broader system compromise, and arbitrary code execution outside the sandbox.

No specific vendor workaround or temporary mitigation is provided in the cited advisories. Until patching is completed, reduce exposure by enforcing least privilege, avoiding administrative user contexts, restricting access to untrusted web content, enabling host and browser exploit mitigations, and using endpoint detection/prevention controls. These measures may reduce risk but do not remediate the underlying sandbox escape.

Upgrade affected Mozilla products to fixed versions. The content states this vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12. Where applicable, follow vendor-packaged updates such as Debian firefox-esr 140.12.0esr-1~deb13u1 or later. Older versions should be considered vulnerable.