---
title: "Two critical PHP flaws let attackers run code on web servers; fixed versions are out and AI helped find them"
url: https://anawords.com/story/php2shell-critical-php-flaws-cve-2026-109618-patch-now
published: 2026-10-22T16:37:53+05:30
updated: 2026-10-22T16:37:53+05:30
section: Safety & Trust
author: Mayank Sahu
checked: sources checked by AI, approved by editor
version: 1
---

# Two critical PHP flaws let attackers run code on web servers; fixed versions are out and AI helped find them

PHP 8.5.12, 8.4.27, 8.3.36 and 8.2.35 fix the “PHP2Shell” bugs. Amazon saw an exploitation attempt four days before disclosure, and researchers say AI models helped find and test the flaws.

**In short:** Two critical flaws in PHP, tracked as CVE-2026-109618 and CVE-2026-109619 and nicknamed “PHP2Shell”, can let an attacker run code on a web server without logging in. The PHP project released fixed versions on 21 October 2026, and security firms report the flaws are being exploited. Researchers who found them say they used AI models in their work.

## What happened

The PHP project released emergency security updates on 21 October 2026 for two flaws that can let an attacker take over a web server running PHP with a single request, before any website code runs.[^1][^2] PHP powers a large share of websites, so the fixes matter to almost anyone who runs a site or app on it.

The two bugs are:[^2]

- **CVE-2026-109618:** a flaw in how PHP handles running out of memory. If memory runs out while request data is only partly set up, the clean-up step treats that data as valid.
- **CVE-2026-109619:** leftover state from one request points to freed memory, which a later request on the same worker can use. PHP’s advisory also lists memory disclosure as an impact.

Both are rated 9.2 out of 10 on the CVSS v4.0 scale by the PHP security team. Identifiers that circulated before release carried an incorrect score of 10.0.[^2]

## Which versions are affected and fixed

| Branch | Fixed version |
|---|---|
| PHP 8.5 | 8.5.12 |
| PHP 8.4 | 8.4.27 |
| PHP 8.3 | 8.3.36 |
| PHP 8.2 | 8.2.35 |

PHP 7.4 to 8.1 get only minimal source backports, and PHP 5.4 to 7.3 are past end of life with no fix from the PHP project.[^1][^2] Help Net Security says every PHP setup that serves web requests is affected, including PHP-FPM, Apache with mod_php, php-cgi, FrankenPHP and LiteSpeed.[^1]

## Exploitation has started

Amazon Threat Intelligence recorded an exploitation attempt against its honeypots on 17 October, four days before public disclosure; how the attacker got the details is unknown.[^1][^2] Amazon says the flaws are now being broadly exploited, and Cloudflare reports early attacks.[^2] The UK’s NCSC urges taking offline any system that cannot be fixed right away.[^1]

## AI’s part in the discovery

The PHP Foundation credited Calif, OpenAI and Wiz, among others, for research and responsible disclosure. Calif and Wiz both said they used AI models in their research.[^2] Help Net Security notes that frontier AI models substantially lowered the barrier to turning the flaws into an exploit.[^1] This is a clear example of AI cutting both ways: it can help defenders find bugs faster, and it can help attackers use them faster.

## What to do now

- **Update PHP** to a fixed version. PHP says updating is the only complete fix.[^2]
- **If you cannot update yet**, Tenable lists interim settings: set `memory_limit=-1` so applications cannot override it, and set `session.upload_progress.enabled=0` (plus `fatal_error_backtraces=0` on PHP 8.5), then restart every PHP worker.[^2]
- **On shared hosting**, check your host’s PHP version in its control panel and ask support if it is not patched.
- **Investigate from 17 October**, not the disclosure date, as Amazon recommends.[^2]

## What it means

For small businesses and bloggers in India and elsewhere, most PHP sites run on shared hosting or managed WordPress, where the host updates PHP. The practical step is to confirm that has happened, not assume it. Developers running their own servers should treat this as an emergency patch. The longer lesson is that the time between a bug being found and being used is shrinking, partly because of AI. Teams that can patch within a day will be better protected than those that patch monthly.

## What to watch

- Host and Linux distribution advisories confirming patched packages.
- Whether working public exploit code is confirmed; Tenable had not verified any when it published.[^2]

Related: [a hacker’s use of AI agents against 100+ websites](/story/hacker-ai-agents-breached-100-company-websites-norforge) and [Microsoft’s new controls for AI agents](/story/microsoft-agentic-insider-controls-agent-risk-score).

## Fact ledger

- [Reported] PHP released fixes on 21 October 2026 for CVE-2026-109618 and CVE-2026-109619, which allow remote code execution. (source 1,2)
- [Reported] Fixed versions are 8.5.12, 8.4.27, 8.3.36 and 8.2.35. (source 1,2)
- [Reported] Amazon recorded an exploitation attempt on 17 October, four days before disclosure. (source 1,2)
- [Unconfirmed] Both flaws are rated CVSS v4.0 9.2. (source 2)
- [Unconfirmed] The PHP Foundation credited Calif, OpenAI and Wiz; Calif and Wiz said they used AI models. (source 2)
- [Not known] How the attacker obtained details before disclosure.

## Sources

1. [Help Net Security: PHP2Shell, critical PHP vulnerabilities patched, update now](https://www.helpnetsecurity.com/2026/10/21/php2shell-php-vulnerabilities-patched-cve-2026-109618-cve-2026-109619/)
2. [Tenable: PHP2Shell (CVE-2026-109618, CVE-2026-109619) FAQ](https://www.tenable.com/blog/php2shell-cve-2026-109618-cve-2026-109619-frequently-asked-questions-about-critical-php-remote)