CVE-2026-3388
📋 TL;DR
CVE-2026-3388 is an uncontrolled recursion vulnerability in Squirrel programming language versions up to 3.2. This allows local attackers to cause denial of service through resource exhaustion by triggering infinite recursion in compiler functions. Only systems running vulnerable Squirrel interpreters or applications built with Squirrel are affected.
💻 Affected Systems
- Squirrel programming language
- Applications using Squirrel scripting engine
📦 What is this software?
Squirrel by Squirrel Lang
⚠️ Risk & Real-World Impact
Worst Case
Complete system crash or denial of service due to stack exhaustion, potentially leading to application termination and service disruption.
Likely Case
Application crash or hang requiring restart, causing temporary service interruption for affected processes.
If Mitigated
Application termination with automatic restart capabilities limiting downtime to seconds/minutes.
🎯 Exploit Status
Proof-of-concept available on GitHub; exploit requires local code execution through Squirrel interpreter.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: None - project has not responded to vulnerability report
Restart Required: Yes
Instructions:
No official patch available. Monitor Squirrel GitHub repository for updates. Consider alternative mitigations if critical.
🔧 Temporary Workarounds
Restrict Squirrel Script Execution
allLimit ability to execute untrusted Squirrel scripts through application controls or permissions.
Implement Resource Limits
linux/windowsConfigure system or application resource limits (stack size, CPU time) to contain impact.
ulimit -s 8192 # Linux stack limit example
Set-ProcessMitigation -Name squirrel.exe -Enable DisallowWin32kSystemCalls # Windows example
🧯 If You Can't Patch
- Isolate Squirrel applications in containers or VMs with resource constraints
- Implement strict access controls to prevent unauthorized users from executing Squirrel scripts
🔍 How to Verify
Check if Vulnerable:
Check Squirrel version: run 'squirrel -v' or check application dependencies for Squirrel <= 3.2Check Version:
squirrel -v 2>&1 | grep -i version || echo "Check application documentation for Squirrel version"Verify Fix Applied:
No fix available to verify; monitor for Squirrel updates beyond version 3.2📡 Detection & Monitoring
Log Indicators:
- Application crashes with stack overflow errors
- High CPU usage followed by process termination
- Squirrel compiler segmentation faults
Network Indicators:
- None - purely local exploitation
SIEM Query:
Process: (squirrel OR sq*) AND (EventID: 1000 OR "stack overflow" OR "segmentation fault")