This vulnerability involves incorrect boundary conditions in the Widget: Win32 component of Mozilla Firefox, which can lead to a sandbox escape. The sandbox escape vulnerability was resolved in Firefox 156 and Firefox ESR 153.3. The vendor advisory confirms the fix and classifies the impact as high. No known exploits in the wild have been reported at this time.

The vulnerability allows an attacker to escape the sandbox environment in Firefox, which could lead to privilege escalation or unauthorized access beyond the browser sandbox. The impact is rated high by the vendor. There are no reports of active exploitation in the wild.

An official fix is available. Users should update to Firefox 156 or later, or Firefox ESR 153.3 or later, to remediate this vulnerability. No additional mitigation steps are required beyond applying the update.