CVE-2026-4009: SoLoud WAV Parser Buffer Overflow Flaw

CVE-2026-4009 Overview

A vulnerability has been identified in the SoLoud audio library (jarikomppa/soloud) up to version 20200207. The vulnerability affects the drwav_read_pcm_frames_s16__msadpcm function within the WAV File Parser component located in src/audiosource/wav/dr_wav.h. This out-of-bounds read vulnerability can be exploited through local access, potentially leading to information disclosure or application crashes when processing maliciously crafted WAV files.

Critical Impact

Local attackers can trigger an out-of-bounds read condition by supplying a specially crafted WAV file to applications using the vulnerable SoLoud library, potentially causing denial of service or memory disclosure.

Affected Products

• SoLoud audio library versions up to 20200207
• Applications incorporating the vulnerable dr_wav.h WAV file parser
• Software projects using SoLoud's MSADPCM audio decoding functionality

Discovery Timeline

• 2026-03-12 - CVE-2026-4009 published to NVD
• 2026-03-12 - Last updated in NVD database

Technical Details for CVE-2026-4009

Vulnerability Analysis

This vulnerability is classified as CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer). The flaw exists within the MSADPCM (Microsoft Adaptive Differential Pulse Code Modulation) decoding routine in the dr_wav header-only library, which is bundled within SoLoud. When processing WAV files encoded with MSADPCM compression, the drwav_read_pcm_frames_s16__msadpcm function fails to properly validate buffer boundaries before reading audio sample data.

The exploit has been publicly disclosed and a reproduction case is available. The vulnerability requires local access to exploit, as an attacker must supply a malicious WAV file to an application using the vulnerable library.

Root Cause

The root cause stems from insufficient bounds checking in the MSADPCM decoding path within src/audiosource/wav/dr_wav.h. When parsing the block predictors and sample data from an MSADPCM-encoded WAV file, the function does not adequately verify that the requested read operations remain within the allocated buffer boundaries. A malformed WAV file with manipulated header values (such as incorrect block sizes or sample counts) can cause the decoder to read beyond the intended buffer limits.

Attack Vector

This is a local attack vector vulnerability requiring the attacker to provide a maliciously crafted WAV file to an application utilizing the vulnerable SoLoud library. The attack scenario involves:

1. An attacker crafts a WAV file with malformed MSADPCM encoding parameters
2. The victim's application loads the malicious WAV file using SoLoud's audio processing functions
3. The drwav_read_pcm_frames_s16__msadpcm function processes the file and reads beyond allocated memory
4. This can result in information disclosure, application crash, or potential further exploitation

The vulnerability mechanism involves improper handling of MSADPCM block structure parsing in the WAV file decoder. When the decoder processes malformed audio frame data, it fails to validate that read operations stay within buffer boundaries. For technical details and a reproduction case, see the GitHub Issue #401 and the reproduction case repository.

Detection Methods for CVE-2026-4009

Indicators of Compromise

• Unexpected application crashes when loading or playing WAV audio files
• Memory access violations or segmentation faults in applications using SoLoud
• Abnormal memory read patterns detected during WAV file processing
• Core dumps showing crashes within drwav_read_pcm_frames_s16__msadpcm or related dr_wav functions

Detection Strategies

• Monitor for application crashes with stack traces pointing to SoLoud's WAV parsing functions
• Implement file integrity monitoring for WAV files being processed by vulnerable applications
• Use memory sanitizers (AddressSanitizer, Valgrind) during development to detect out-of-bounds reads
• Deploy runtime application self-protection (RASP) to detect memory corruption attempts

Monitoring Recommendations

• Enable crash reporting and analyze dumps for patterns indicating exploitation attempts
• Monitor file access logs for suspicious WAV file activity targeting applications using SoLoud
• Implement logging around audio file loading operations in applications using the vulnerable library

How to Mitigate CVE-2026-4009

Immediate Actions Required

• Upgrade SoLoud to version 20200207 or later as recommended by the advisory
• Audit applications that incorporate SoLoud or dr_wav to identify vulnerable deployments
• Restrict access to untrusted WAV files in applications using vulnerable versions
• Consider implementing input validation on audio files before passing them to SoLoud

Patch Information

The recommended remediation is to upgrade the SoLoud library to version 20200207 or later. The project maintainers were informed through GitHub Issue #401, though no official response has been received at the time of publication. Organizations should monitor the SoLoud repository for updates and patches.

For additional technical details, refer to the VulDB analysis.

Workarounds

• Implement pre-processing validation of WAV files before passing them to SoLoud
• Use alternative audio libraries for processing untrusted WAV files until patches are applied
• Sandbox applications that process untrusted audio files to limit the impact of exploitation
• Disable MSADPCM audio format support if not required by your application

# Verify SoLoud version in your project
grep -r "SOLOUD_VERSION" /path/to/project/
# Check for vulnerable dr_wav.h usage
find /path/to/project -name "dr_wav.h" -exec head -50 {} \;