CVE-2026-3382: ChaiScript Buffer Overflow Vulnerability

CVE-2026-3382 Overview

A memory corruption vulnerability has been discovered in ChaiScript up to version 6.1.0. The vulnerability affects the function chaiscript::Boxed_Number::get_as located in the file include/chaiscript/dispatchkit/boxed_number.hpp. Successful exploitation of this flaw can lead to memory corruption, potentially causing application crashes or other undefined behavior. This vulnerability requires local access to exploit.

Critical Impact

Memory corruption in ChaiScript's Boxed_Number handling could lead to denial of service or potentially arbitrary code execution in applications embedding the ChaiScript scripting engine.

Affected Products

• ChaiScript versions up to and including 6.1.0
• Applications embedding vulnerable ChaiScript versions
• Systems running ChaiScript-based scripts locally

Discovery Timeline

• 2026-03-01 - CVE CVE-2026-3382 published to NVD
• 2026-03-05 - Last updated in NVD database

Technical Details for CVE-2026-3382

Vulnerability Analysis

This vulnerability is classified as both CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and CWE-787 (Out-of-Bounds Write). The flaw resides in the chaiscript::Boxed_Number::get_as function within the boxed_number.hpp header file, which is part of ChaiScript's dispatch kit responsible for handling boxed number types.

The vulnerability requires local access to exploit, meaning an attacker would need to be able to execute ChaiScript code on the target system or manipulate ChaiScript scripts that are processed by an application embedding the library. The exploit has been publicly released, increasing the risk of active exploitation.

The ChaiScript project was notified of this vulnerability through an issue report on their GitHub repository, but as of the publication date, no official response has been provided.

Root Cause

The root cause stems from improper memory boundary handling within the get_as function in the boxed_number.hpp file. When processing certain inputs, the function fails to properly validate memory boundaries, leading to out-of-bounds write operations. This type of memory corruption can occur when the function attempts to convert or access boxed number values without adequate bounds checking.

Attack Vector

The attack vector is local, requiring an attacker to have the ability to execute malicious ChaiScript code on the target system. This could be achieved through:

1. Direct access to a system running ChaiScript-based applications
2. Supplying malicious ChaiScript files to be processed by vulnerable applications
3. Exploiting applications that accept user-provided ChaiScript code without proper sandboxing

The vulnerability exists in the number handling dispatch mechanism, where manipulated input can trigger memory corruption during the type conversion process. Technical details regarding the specific exploitation technique can be found in the GitHub Issue #635 reported to the ChaiScript project.

Detection Methods for CVE-2026-3382

Indicators of Compromise

• Unexpected crashes in applications using ChaiScript, particularly during number conversion operations
• Memory access violations or segmentation faults in processes utilizing the ChaiScript library
• Abnormal memory consumption patterns in ChaiScript-embedded applications

Detection Strategies

• Monitor application logs for crashes originating from boxed_number.hpp or the get_as function
• Implement memory sanitizers (AddressSanitizer, MemorySanitizer) during development and testing of ChaiScript-based applications
• Review and audit any ChaiScript files processed by production systems for suspicious patterns
• Use SentinelOne's Singularity platform to detect memory corruption exploitation attempts at runtime

Monitoring Recommendations

• Enable verbose logging for applications embedding ChaiScript to capture exception details
• Monitor process memory usage for anomalies that may indicate exploitation attempts
• Implement file integrity monitoring for ChaiScript files in production environments

How to Mitigate CVE-2026-3382

Immediate Actions Required

• Review all applications in your environment that embed ChaiScript and identify those running version 6.1.0 or earlier
• Restrict access to systems capable of executing ChaiScript code to trusted users only
• Audit ChaiScript files processed by applications for potentially malicious content
• Consider temporarily disabling ChaiScript functionality in critical applications until a patch is available

Patch Information

As of the last update on 2026-03-05, no official patch has been released by the ChaiScript project. The maintainers were notified through GitHub Issue #635 but have not yet responded. Organizations should monitor the ChaiScript GitHub repository for updates and apply patches immediately when available.

Workarounds

• Implement input validation and sanitization for any ChaiScript code before processing
• Run ChaiScript-embedded applications in sandboxed environments with limited privileges
• Restrict local access to systems running ChaiScript applications to trusted personnel only
• Consider using application whitelisting to control which ChaiScript files can be executed

# Configuration example - Restrict ChaiScript file execution permissions
chmod 640 /path/to/chaiscript/files/*.chai
chown root:chaiscript-users /path/to/chaiscript/files/*.chai

# Enable sandboxing for ChaiScript applications (example using firejail)
firejail --private --net=none /path/to/chaiscript-app