CVE-2026-2659
📋 TL;DR
This vulnerability in Squirrel (up to version 3.2) allows local attackers to trigger an out-of-bounds read via manipulation of the _target_stack argument in the SQFuncState::PopTarget function. This could potentially lead to information disclosure or crash of the Squirrel interpreter. Only systems running vulnerable versions of Squirrel are affected.
💻 Affected Systems
- Squirrel programming language
📦 What is this software?
Squirrel by Squirrel Lang
⚠️ Risk & Real-World Impact
Worst Case
Information disclosure through memory read, potential denial of service via application crash, or possible escalation to arbitrary code execution if combined with other vulnerabilities.
Likely Case
Application crash leading to denial of service, or limited information disclosure from adjacent memory.
If Mitigated
Minimal impact if proper sandboxing or privilege separation is in place, as exploitation requires local access.
🎯 Exploit Status
Exploit requires local access and manipulation of specific function arguments. Public proof-of-concept exists in GitHub repository.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: Not available - project has not responded to issue report
Restart Required: Yes
Instructions:
No official patch available. Monitor the Squirrel GitHub repository for updates. Consider alternative mitigations.
🔧 Temporary Workarounds
Input Validation and Sanitization
allImplement strict input validation for any Squirrel script execution, particularly for arguments passed to vulnerable functions.
Application Sandboxing
allRun Squirrel interpreter in a sandboxed environment with limited permissions to contain potential damage.
🧯 If You Can't Patch
- Restrict local access to systems running vulnerable Squirrel applications
- Implement network segmentation to limit lateral movement potential
🔍 How to Verify
Check if Vulnerable:
Check Squirrel version: if using version 3.2 or earlier, system is vulnerable. Review application dependencies for Squirrel inclusion.Check Version:
For compiled applications: check build dependencies. For source: review squirrel/squirrel.h or similar version files.Verify Fix Applied:
Verify Squirrel version is updated beyond 3.2 once patch becomes available.📡 Detection & Monitoring
Log Indicators:
- Application crashes with segmentation faults or access violations
- Unusual memory access patterns in application logs
Network Indicators:
- Not applicable - local exploitation only
SIEM Query:
Application: "squirrel" AND (EventID: "1000" OR "Application Error") OR Process: "*squirrel*" AND Termination: "abnormal"