CVE-2026-105838 in libmikmod
Summary
by MITRE • 10/06/2026
libmikmod before 3.3.14 contains a heap out-of-bounds read vulnerability in the Impulse Tracker loader load_it.c that allows attackers to read adjacent heap memory via oversized patterns. Attackers can supply a crafted IT module with more than 200 pattern rows, causing IT_ConvertTrack() to read past the itpat buffer and crash applications.
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Analysis
by VulDB Data Team • 10/06/2026
The vulnerability identified in libmikmod versions prior to 3.3.14 represents a critical heap-based out-of-bounds read flaw located within the Impulse Tracker loader module, specifically in the file load_it.c. This library is widely used for decoding and playing various tracker music formats on embedded systems and desktop applications, making its security integrity paramount for any software relying on it for audio processing. The core of the issue stems from insufficient validation of input data structures when parsing IT modules, which are a specific type of tracker file format characterized by patterns that define musical sequences. When an attacker supplies a crafted IT module containing more than two hundred pattern rows, the internal logic fails to properly bound-check array accesses during the conversion process. This lack of rigorous boundary verification allows the application to read memory locations adjacent to the intended buffer, exposing sensitive heap data that should remain inaccessible to untrusted input sources.
From a technical perspective, this flaw is classified under CWE-125, which denotes Out-of-bounds Read vulnerabilities. The specific mechanism involves the IT_ConvertTrack function, which processes track data from the module file. When processing an oversized pattern with excessive rows, the pointer arithmetic used to access elements within the itpat buffer exceeds its allocated limits. Instead of triggering a segmentation fault or raising an exception immediately due to stack corruption, this particular flaw results in reading adjacent heap memory. This behavior is particularly dangerous because it can lead to information disclosure, where attackers may extract cryptographic keys, session tokens, or other sensitive data stored in neighboring memory regions. Furthermore, the ability to read arbitrary heap contents can facilitate further exploitation chains, such as bypassing security mitigations like Address Space Layout Randomization by leaking pointer addresses, thereby enabling more sophisticated attacks including remote code execution if combined with other vulnerabilities.
The operational impact of this vulnerability is significant for any application that utilizes libmikmod to process user-supplied or untrusted audio files. An attacker can exploit this flaw remotely by distributing a malicious IT module through email attachments, web uploads, or network streams. Upon loading the crafted file, the target application will read out-of-bounds memory, which typically results in an immediate crash due to accessing invalid memory pages or corrupted data structures. This constitutes a denial of service condition against the affected software. However, beyond simple crashes, the potential for information leakage poses a severe confidentiality risk. In environments where libmikmod is embedded within larger applications, such as media players or game engines, this vulnerability could compromise the entire application's security posture by leaking internal state data to an external attacker who controls the input file format.
To mitigate this risk, organizations and developers must immediately upgrade libmikmod to version 3.3.14 or later, where these boundary checks have been implemented in the load_it.c module. For applications that cannot be updated instantly due to dependency constraints, implementing strict validation of IT module headers before passing them to the library is recommended. Specifically, checking the number of pattern rows and ensuring they do not exceed expected limits can prevent triggering the vulnerable code path. Additionally, deploying runtime application self-protection mechanisms or using memory-safe languages for new developments can reduce the attack surface associated with such low-level buffer handling errors. From a defensive standpoint, monitoring for unusual heap access patterns or crashes in applications linked against libmikmod can help detect exploitation attempts in real-time. This vulnerability aligns with ATT&CK technique T1046, Network Service Scanning, if used to probe for vulnerable services, and more critically relates to data exfiltration techniques where sensitive information is read from memory via crafted inputs. Ensuring that all third-party libraries are kept up-to-date remains the most effective strategy against such common implementation flaws in multimedia processing software.