The FBI continues to warn about two critical security flaws in PHP, a programming language used to build many websites and online services. Attackers could exploit these vulnerabilities to break into systems, putting sensitive information and business operations at risk. Security updates are available and should be applied immediately. If you are a business owner or website operator, check whether your systems are affected. Contact your IT support team, website developer, or hosting provider for help identifying vulnerable systems and applying the necessary updates. The FBI urges organizations to take the following steps now: ➡️ If an immediate update is not feasible it is recommended that organizations take the system offline until it can be fully mitigated. ➡️ Immediately update affected PHP installations following the guidance on php.net. Inventory where PHP runs in your environment, prioritizing internet-facing systems and vendor products that bundle PHP. ➡️ Monitor web servers for suspicious activity, including PHP processes unexpectedly launching command shells or downloading files. Ensure appropriate process-monitoring capabilities are in place to help identify potential exploitation. ➡️ If you find signs of compromise, isolate affected systems, preserve your web server and PHP logs, and report it to your local FBI field office or ic3.gov. Those reports help us identify the actors involved and warn other organizations before they become victims. For the latest information on these vulnerabilities (CVE-2026-109618 and CVE-2026-109619), follow PHP’s announcements on php.net, CERT-EU Security Advisory 2026-018, and CISA’s Known Exploited Vulnerabilities catalog.