This cloud security stock is crashing after the company reported weak guidance

Shares of Qualys tanked by more than 23% in after-hours trading, after the company reported first quarter earnings and lowered its guidance for full-year revenues.

The cloud security company reported revenues of $37.5 million, up 24% from the quarter a year ago, but below analysts' estimates of $40 million, according to Bloomberg.

The company reported diluted earnings per share of 15 cents, better than the estimate for 11 cents.

CEO Philippe Courtot said in the statement: "We had a good quarter with continued success across our business, including laying the groundwork for three major new services that we launched at the RSA Conference last month. These launches, which collectively double our addressable market, include: first and foremost, our disruptive Cloud Agent Platform; second, the seamless integration of our Web Application Scanning and Web Application Firewall services, which is an industry first; and third, the extension to internal networks of our successful Continuous Monitoring solution for perimeters."

The company expects 2015 revenues of between $165 and $166.5 million, down from the range of $167.3 million - $169.3 million earlier guided. It's a 26% decline from the midpoint of their previous range, and would be a 24% increase from 2014 revenues.

Analysts had expected full-year revenues of $168.4 for the year, according to MarketWatch.

The stock closed 6% higher on Monday at $55.28 per share. It's up 46% year-to-date and a whopping 187% over the past 12 months.

It has a market cap of $1.8 billion.