CVE-2026-24818: UEVR Buffer Overflow Vulnerability

CVE-2026-24818 Overview

CVE-2026-24818 is an Out-of-bounds Read vulnerability affecting the UEVR (Universal Unreal Engine VR) project by praydog. The vulnerability exists within the dependencies/lua/src modules, specifically associated with the lparser.c file. This security flaw allows attackers to read memory beyond the intended buffer boundaries, potentially leading to information disclosure or application crashes.

Critical Impact

This out-of-bounds read vulnerability could allow remote attackers to access sensitive memory contents or cause denial of service conditions in applications using the affected UEVR versions.

Affected Products

• UEVR versions prior to 1.05
• Applications utilizing the vulnerable Lua parser component (lparser.c)
• Systems running UEVR with the affected dependencies/lua/src modules

Discovery Timeline

• 2026-01-27 - CVE CVE-2026-24818 published to NVD
• 2026-01-27 - Last updated in NVD database

Technical Details for CVE-2026-24818

Vulnerability Analysis

The vulnerability is classified as CWE-125 (Out-of-bounds Read), a memory safety issue that occurs when the application reads data past the end or before the beginning of an intended buffer. In this case, the flaw manifests within the Lua parser component (lparser.c) bundled with UEVR.

Out-of-bounds read vulnerabilities in parser components are particularly concerning because parsers typically process untrusted input data. When the parser attempts to access memory outside the allocated buffer boundaries during parsing operations, it can expose sensitive data from adjacent memory regions or trigger undefined behavior that leads to application instability.

Root Cause

The root cause lies in improper bounds checking within the lparser.c file located in the dependencies/lua/src modules. The Lua parser fails to properly validate array indices or pointer offsets before performing read operations, allowing access to memory locations outside the intended buffer boundaries. This type of vulnerability typically occurs when:

• Array index calculations do not account for edge cases
• Loop termination conditions are incorrectly specified
• Pointer arithmetic operations lack proper boundary validation

Attack Vector

The vulnerability is exploitable over the network without requiring authentication or user interaction. An attacker could craft malicious input that triggers the out-of-bounds read condition when processed by the vulnerable Lua parser. The attack could be delivered through:

• Maliciously crafted Lua scripts or data structures processed by UEVR
• Network-based payloads targeting applications that expose the vulnerable parser functionality
• Content injection attacks against systems using UEVR for VR modification

The vulnerability may allow attackers to leak sensitive memory contents, bypass security controls through information disclosure, or cause denial of service through application crashes when invalid memory regions are accessed.

Detection Methods for CVE-2026-24818

Indicators of Compromise

• Unusual crash reports or application terminations related to Lua parsing operations
• Memory access violations or segmentation faults in lparser.c or related Lua modules
• Unexpected read operations on memory addresses outside normal application boundaries

Detection Strategies

• Monitor for application crashes with stack traces referencing lparser.c or Lua parser components
• Implement memory safety monitoring tools to detect out-of-bounds read attempts
• Deploy application-level logging for Lua script processing operations

Monitoring Recommendations

• Enable verbose logging for UEVR and its Lua processing components
• Implement runtime application self-protection (RASP) solutions to detect memory access anomalies
• Monitor system logs for repeated crash patterns indicative of exploitation attempts

How to Mitigate CVE-2026-24818

Immediate Actions Required

• Upgrade UEVR to version 1.05 or later immediately
• Review any custom Lua scripts or configurations processed by UEVR for malicious content
• Implement network segmentation to limit exposure of systems running vulnerable UEVR versions

Patch Information

The vulnerability has been addressed in UEVR version 1.05. The fix implements proper bounds checking within the lparser.c file to prevent out-of-bounds read conditions. Organizations should update to the patched version as soon as possible.

For technical details regarding the fix, refer to the GitHub Pull Request #337 which contains the security patch.

Workarounds

• Restrict network access to systems running vulnerable UEVR versions until patching is complete
• Implement input validation and sanitization for any Lua scripts or data processed by UEVR
• Consider deploying Web Application Firewalls (WAF) or intrusion prevention systems to filter potentially malicious input

# Verify UEVR version to confirm patch status
# Ensure version is 1.05 or later
# Update UEVR from official repository
git pull origin main
git checkout tags/v1.05

# Alternatively, download the latest release from GitHub
# https://github.com/praydog/UEVR/releases