A flaw in the Application Update component of Mozilla Firefox allows an attacker to gain elevated privileges. By exploiting this weakness, an adversary can run code with higher authority than intended, potentially compromising the entire system. The vulnerability is explicitly labeled as a privilege escalation issue and is formally addressed in official security advisories.

Mozilla Firefox versions earlier than 158 and Firefox ESR versions earlier than 153.5 are vulnerable. The flaw is fixed in Firefox 158 and Firefox ESR 153.5, so any installation not yet updated to these releases is at risk.

The EPSS score is not available and the vulnerability is not listed in CISA KEV, indicating no publicly documented exploits. Nonetheless, the impact of privilege escalation is severe, and the attack could occur through the Application Update mechanism, potentially requiring execution of malicious update files. The lack of known exploits does not diminish the risk posed by the flaw, especially in environments where software updates are manually handled or legacy systems remain unpatched.