Firefox 12.51 52 Esr -

Firefox 52 ESR reached end-of-life in September 2018. Since then, hundreds of critical security vulnerabilities (CVEs) have been discovered, including remote code execution flaws. Using it on a networked computer is a major risk.

So where does the .51 come from? The most plausible explanations are: firefox 12.51 52 esr

Firefox 52 ESR (Extended Support Release) remains a legendary version in web history, primarily because it served as the final "lifeboat" for users on legacy operating systems and those dependent on specialized web technologies. Firefox 52 ESR reached end-of-life in September 2018