CVE-2026-102804 in stb
Summary
by MITRE • 09/30/2026
A vulnerability was detected in Nothings stb up to 2c980bb59875b0d32144a71867fbdebb2f77cd20. The impacted element is the function hexwave_init in the library stb_hexwave.h. Performing a manipulation of the argument width/oversample results in integer overflow. Remote exploitation of the attack is possible. The exploit is now public and may be used. The project was informed of the problem early through an issue report but has not responded yet.
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Analysis
by VulDB Data Team • 09/30/2026
The stb libraries, specifically the single-file header files developed by Sean Barrett, are widely adopted in the software industry for their simplicity and ease of integration into various projects ranging from game development to image processing applications. A critical security flaw has been identified within the hexwave initialization functionality located in the stb_hexwave.h module prior to commit 2c980bb59875b0d32144a71867fbdebb2f77cd20. This vulnerability stems from a fundamental arithmetic error during the calculation of buffer sizes or array dimensions based on user-supplied parameters for width and oversampling factors. When these inputs are manipulated by an attacker, they trigger an integer overflow condition that compromises the integrity of memory allocation operations within the library.
The technical nature of this flaw is classified as an Integer Overflow leading to a Buffer Overread or potentially a Heap-Based Buffer Overflow depending on how the subsequent memory access patterns behave after the miscalculation. In C programming languages, which underpin these libraries, integer types have fixed ranges and do not automatically check for arithmetic overflows. When the product of width and oversample exceeds the maximum value representable by the data type used for size calculation, it wraps around to a small positive number or zero. The application then proceeds to allocate memory based on this incorrect, significantly smaller size while subsequently attempting to write or read data corresponding to the original larger dimensions. This discrepancy creates an out-of-bounds access scenario where the program reads from or writes to memory locations outside the allocated buffer boundaries.
From a threat modeling perspective, this vulnerability aligns with CWE-190 Integer Overflow or Wraparound and often leads directly to CWE-787 Out-of-Bounds Write if the overflow results in writing beyond the heap boundary, or CWE-125 Out-of-Bounds Read if it involves reading past allocated memory. The presence of such a flaw allows for remote exploitation because many applications that utilize stb libraries process untrusted media files or network data streams without sufficient validation of input parameters before passing them to hexwave_init. An attacker can craft malicious inputs containing specifically crafted width and oversample values designed to trigger the overflow, thereby gaining control over memory layout and potentially achieving arbitrary code execution with the privileges of the affected application.
The operational impact of this vulnerability is severe due to its remote exploitability and the public availability of proof-of-concept exploits. Since stb libraries are often embedded directly into source code rather than linked as external dependencies, vulnerabilities within them affect a vast number of downstream applications that may not be aware they contain vulnerable code. The fact that the project maintainers have been notified but have not yet issued a patch or update means that organizations relying on this library remain exposed to active exploitation attempts. Attackers leveraging public exploit kits can target systems running affected versions, leading to potential data exfiltration, denial of service through application crashes, or full system compromise depending on the context in which the vulnerable function is invoked.
Mitigation strategies must be implemented immediately given the lack of an official patch from upstream. Developers should audit their codebases for direct usage of stb_hexwave.h and replace it with a patched version if available from alternative forks or community-maintained repositories that have addressed this specific commit range. Alternatively, applications can implement strict input validation logic before calling hexwave_init to ensure that width and oversample values fall within safe mathematical bounds that cannot cause integer overflow when multiplied. This includes checking for maximum allowable dimensions and ensuring the multiplication result does not exceed standard buffer size limits defined by the application architecture. Additionally, enabling compiler-based security features such as stack canaries, Address Space Layout Randomization, and Control Flow Integrity can help mitigate the impact of successful exploitation attempts by making it harder to chain this vulnerability into arbitrary code execution.
Long-term remediation requires a shift in dependency management practices for projects using single-file header libraries. Organizations should consider maintaining their own internal copies of these headers with regular security audits rather than relying on raw upstream versions that may lag in patch deployment. Integrating static analysis tools capable of detecting integer overflow patterns and dynamic testing methods like fuzzing against the hexwave initialization function can help identify similar flaws before they reach production environments. Furthermore, participating in coordinated disclosure processes ensures that vulnerabilities are addressed promptly by maintainers while allowing users time to apply mitigations, reducing the window of exposure during which public exploits remain effective.