Security | Threat Detection | Cyberattacks | DevSecOps | Compliance

New Snyk research across thousands of scanned enterprise environments shows why a high model-risk score marks where triage begins, and how security teams should respond.

On October 20, 2026, the PHP security team issued an advance security advisory regarding two critical vulnerabilities, CVE-2026-109618 and CVE-2026-109619, affecting core PHP source code. Both vulnerabilities carry a critical-severity CVSS v4.0 score of 9.2 and could potentially allow unauthenticated remote code execution (RCE) on affected servers. The official patched PHP releases are now available.

We recently collaborated with OpenAI, PHP, and a number of other organizations to respond to a pair of serious remote code execution vulnerabilities in PHP that are likely to impact the majority of the world's public web servers. PHP underpins a large part of the web, powering content management systems, online stores, and business applications. Its security matters to vital services that millions of people and organizations rely on daily.

Today, Calif.io, Wiz, OpenAI and Quarkslab disclosed two vulnerabilities in PHP, tracked as CVE-2026-109618 and CVE-2026-109619 and known as php2shell. The vulnerabilities affect all web servers running PHP 5.4 or later and they may allow an attacker to cause denial of service, remote code execution, and data exposure when an application processes specially crafted HTTP traffic.

In response to requests, this update consolidates the Sophos countermeasures that relate the PHP2Shelll vulnerabilities. SophosLabs has developed the following countermeasures to specifically detect activity associated with this threat. The next table lists additional pre-existing Sophos countermeasures that will likely address post-exploitation activity associated with these vulnerabilities.

Two critical remote code execution vulnerabilities have been found in PHP itself. Treat all versions as affected. ‍The vulnerabilities, CVE-2026-109618 and CVE-2026-109619, both have a CVSS v4.0 score of 9.2. The PHP security team will release fixes on October 21, 2026, at 16:00 CEST / 10:00 EDT / 07:00 PT. If you run PHP anywhere in your stack, please stay tuned for workarounds and patches. Be prepared to take action.

The two registers hold different objects, run on different clocks and answer to different people. Where they are treated as one list at different levels of detail, items get counted twice and others fall between them. ‍ A vulnerability register holds findings on assets and numbers in the thousands. A cyber risk register holds loss scenarios and numbers in the tens. Neither is a summary of the other. ‍

The recent disclosure of a major vulnerability in Citrix NetScaler pointed to a widespread weak point: a login page is an attack surface that can be used to compromise and access an application server. Indeed, the disclosures included an actively exploited flaw that allowed attackers to execute commands on affected gateways without signing in. As with any emergency patch, admins had to weigh cutting off or disrupting their users’ access with the risk of delaying a critical security update.