CVE-2026-24817: UEVR Buffer Overflow Vulnerability

CVE-2026-24817 Overview

CVE-2026-24817 is a high-severity Out-of-bounds Write vulnerability affecting praydog UEVR (Universal Unreal Engine VR Mod), specifically within the embedded Lua scripting engine components. The vulnerability exists in the ldebug.c and lvm.c source files located in the dependencies/lua/src modules. This flaw allows an attacker to write data outside the boundaries of allocated memory buffers, potentially leading to application crashes, denial of service, or more severe impacts depending on the execution context.

Critical Impact
Network-accessible out-of-bounds write in Lua interpreter components could result in denial of service or memory corruption affecting UEVR VR mod users.

Affected Products

UEVR versions prior to 1.05
UEVR dependencies/lua/src modules (ldebug.c, lvm.c)
Unreal Engine applications using vulnerable UEVR mod

Discovery Timeline

2026-01-27 - CVE-2026-24817 published to NVD
2026-01-27 - Last updated in NVD database

Technical Details for CVE-2026-24817

Vulnerability Analysis

This vulnerability is classified as CWE-787 (Out-of-bounds Write), a memory corruption flaw that occurs when a program writes data past the end or before the beginning of an intended buffer. In the context of UEVR, the vulnerability resides within the embedded Lua interpreter's debugging (ldebug.c) and virtual machine (lvm.c) components.

Out-of-bounds write vulnerabilities in Lua interpreters are particularly concerning because Lua scripts are often used to extend application functionality. When the Lua VM improperly handles memory boundaries during script execution or debugging operations, malicious input or crafted Lua scripts could trigger memory corruption.

The network-based attack vector indicates that this vulnerability can potentially be exploited remotely without requiring user interaction or special privileges, making it accessible to unauthenticated attackers who can deliver malicious content to UEVR users.

Root Cause

The root cause of CVE-2026-24817 stems from improper bounds checking within the Lua interpreter components bundled with UEVR. Specifically, the ldebug.c and lvm.c files contain code paths that fail to adequately validate array indices or buffer sizes before performing write operations. This allows write operations to exceed allocated memory boundaries when processing certain inputs or executing specific Lua operations.

The vulnerability affects the dependency management of UEVR, where the bundled Lua source files contain the vulnerable code. This is a common pattern where third-party library vulnerabilities propagate to downstream projects.

Attack Vector

The attack vector for this vulnerability is network-based, meaning an attacker could potentially exploit it through:

Malicious Lua Scripts: Crafted Lua scripts that trigger the out-of-bounds write condition when executed by UEVR
Network Content Delivery: If UEVR processes any network-delivered content that gets interpreted by the Lua engine
Mod Configuration Manipulation: Tampering with configuration files or scripts that UEVR loads and processes

The vulnerability does not require authentication or user interaction, and can result in high availability impact with potential secondary impacts on system availability. For technical implementation details and the specific fix, refer to the UEVR Pull Request #336 on GitHub.

Detection Methods for CVE-2026-24817

Indicators of Compromise

Unexpected UEVR crashes or application hangs during VR session initialization
Memory access violation errors in system logs referencing ldebug.c or lvm.c components
Abnormal memory consumption patterns in UEVR processes
Crash dumps indicating write access violations in Lua-related modules

Detection Strategies

Monitor for abnormal process behavior in UEVR instances, particularly unexpected terminations
Implement file integrity monitoring on UEVR installation directories to detect unauthorized modifications to Lua scripts or configuration files
Deploy endpoint detection rules that identify memory corruption patterns in processes executing Lua interpreters
Use SentinelOne's behavioral AI to detect exploitation attempts targeting memory corruption vulnerabilities

Monitoring Recommendations

Enable verbose logging for UEVR if available to capture execution anomalies
Monitor network traffic for suspicious content delivery to systems running UEVR
Track system stability metrics for machines running vulnerable UEVR versions
Implement application whitelisting to control which Lua scripts can be executed by UEVR

How to Mitigate CVE-2026-24817

Immediate Actions Required

Upgrade UEVR to version 1.05 or later immediately
If immediate upgrade is not possible, consider temporarily disabling UEVR until the patch can be applied
Review any custom Lua scripts used with UEVR for potential exploitation vectors
Ensure systems running UEVR have endpoint protection with memory corruption detection capabilities

Patch Information

The vulnerability has been addressed in UEVR version 1.05. The fix is documented in UEVR Pull Request #336 which contains the necessary patches to the ldebug.c and lvm.c files in the dependencies/lua/src modules.

Users should update their UEVR installation by:

Downloading the latest release (1.05 or newer) from the official UEVR repository
Replacing the existing installation with the updated version
Verifying the installation integrity after update

Workarounds

Isolate systems running vulnerable UEVR versions from untrusted network content
Restrict execution of Lua scripts to only trusted, verified sources
Consider running UEVR in a sandboxed environment with limited memory access permissions
Monitor for the official patch and apply as soon as available if running older versions

bash

# Verify UEVR version (check installation directory for version info)
# Ensure you are running version 1.05 or later to be protected

# Download latest release from official repository
# https://github.com/praydog/UEVR/releases

# After updating, verify file integrity of Lua components
# Check that ldebug.c and lvm.c have been updated with the security fix