The vulnerability resides in the WebRTC Networking component of Mozilla Firefox and Thunderbird. It permits the disclosure of confidential information to an attacker. The weakness aligns with CWE‑200. The impact is a privacy breach for users whose data could be captured by malicious web content or network observers.

Mozilla Firefox versions released before the fix in version 158 are affected. No specific sub‑versions are listed, so it is assumed all builds prior to 158 contain the flaw unless otherwise noted by Mozilla.

The CVSS score of 4.3 indicates medium severity. The EPSS score is not available, and the vulnerability is not listed in the CISA KEV catalog, suggesting limited evidence of widespread exploitation. The likely attack vector is from crafted web pages or network traffic while the browser is active, as inferred from the vulnerability’s description. Exploitation requires that the WebRTC feature be enabled within the affected Firefox client.