The updated description details a sandbox escape caused by incorrect boundary conditions in the WebRTC networking component. This flaw allows an attacker to bypass the isolation provided by the browser’s sandbox, potentially executing code or accessing memory locations beyond the intended boundaries. The vulnerability affects the WebRTC stack, which may become a vector for arbitrary code execution once exploited. The fix is included in Firefox 150, Thunderbird 150, and the ESR 140.10.1 builds.

Mozilla Firefox, all releases prior to version 150, and Mozilla Thunderbird, all releases prior to version 150, are affected. The ESR 140.10.1 build (and the corresponding Thunderbird 140.10.1 build) are fixed and do not contain the flaw. Any system running an affected build with WebRTC enabled is potentially vulnerable, while users on other browsers are not impacted.

The CVSS score of 9.6 denotes a very high severity risk. The EPSS score of 0.00045 indicates a very low probability of exploitation, though still non‑zero, and the vulnerability is not listed in CISA's KEV catalog. Attackers could exploit this sandbox escape by sending malicious WebRTC traffic to a vulnerable browser with the component enabled, which could lead to arbitrary code execution within the browser context. The likely attack vector is inferred from the description, as it is not explicitly stated in the input.