Security | Threat Detection | Cyberattacks | DevSecOps | Compliance

AI is changing how vulnerabilities are discovered and exploited for defenders and attackers alike, and the practical effect is that the time organizations have between a flaw being found and a flaw being exploited keeps shrinking. Today, we have more known vulnerabilities than at any point in history, and they’re being exploited faster than ever.

On October 21, 2026, PHP shipped emergency fixes for two flaws that let anyone on the internet run code on a PHP web server, with no login. The weakness behind them had been flagged in 2024 and then sat, partly because nobody had proved it was exploitable. In 2026, researchers working with AI models proved it within days. Exploit attempts started before the fix shipped, and details leaked a day ahead of schedule. That sequence is the real story of PHP2Shell. The bug matters, but speed matters more.

If you run Node.js, update to 26.12.1, 24.22.1 or 22.23.4 now. If you run Python, upgrade the Brotli package to 1.2.1 and brotlicffi to 1.2.1.0. If you run Bun, move to 1.4.4. All three carry a fix for CVE-2026-111497, an out-of-bounds write in Google's Brotli decoder that can let a remote, unauthenticated attacker crash a process, read its memory or potentially run code by sending it crafted compressed data. Google's CVE record scores it 9.2 under CVSS v4.0.

On October 21, 2026, Node.js fixed CVE-2026-111497, now known as Node2Shell. The bug is in its bundled Brotli decoder, the component that unpacks compressed data. A crafted compressed stream makes the decoder write data outside the memory set aside for it, known as an out-of-bounds write. That can overwrite data the application relies on, so an attacker can crash the application, leak memory or run attacker code. Public proof-of-concept code was published within 24 hours.

PHP2Shell is a pair of critical flaws in the PHP interpreter itself, each with a CVSS v4.0 score of 9.2. Both let an unauthenticated attacker run code on a web server with a single crafted web request, or a pair of them, before any application code runs. Because the bug lives in PHP, not in WordPress, Drupal or Magento, every reachable PHP endpoint on an affected server is exposed, including login pages, static forms, and health checks. Every PHP release from the last decade is affected (back to 5.4).

TL;DR: On October 22, 2026, Zero Day Initiative accidentally posted six unpatched Linux kernel vulnerabilities to the public LKML. Two are CVSS 9.0 SMB RCEs; three are local privilege escalation. No mainline patches exist yet. Monitor your distribution and unload exposed modules.

You might not run PHP yourself. That doesn’t mean you’re safe from PHP2Shell, which is why we created the PHP2Shell Security Checklist. Your SaaS provider might use PHP. Your hosting provider might manage PHP runtimes on your behalf. A third-party application could bundle PHP inside a container or software package you didn’t know existed. This is what makes PHP2Shell a supply-chain security concern.