The vulnerability is an information disclosure flaw located in the Networking component of Firefox. If an attacker gains the ability to exploit this flaw, they may read data that should remain confidential—including sensitive user information or network details—thereby compromising the confidentiality of affected systems. The weakness falls under the CWE-200 category, which denotes improper handling of information that can be exposed to unauthorized parties.

Mozilla Firefox users running versions prior to Firefox 158 or the Firefox ESR 153.5 line are affected. Updating to Firefox 158 or any newer release, including the ESR 153.5, resolves the issue.

The CVSS score of 4.3 indicates a moderate severity. EPSS data is not available, and the vulnerability is not listed in the CISA KEV catalog, implying that the likelihood of real‑world exploitation remains uncertain. Nonetheless, because the flaw permits potentially arbitrary disclosure of sensitive data, the risk is significant until the patched release is deployed.