CVE-2026-38343 in FFmpeg
Summary
by MITRE • 08/28/2026
An integer overflow in the libavfilter/vf_scale.c component of FFmpeg N-122528-gdd2976b9e1 allows attackers to cause a Denial of Service (DoS) via supplying a crafted video file.
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Analysis
by VulDB Data Team • 08/28/2026
The vulnerability identified within the FFmpeg library, specifically in the libavfilter/vf_scale.c component associated with commit dd2976b9e1 and version N-122528-gdd2976b9e1, represents a critical integer overflow issue that compromises the stability of video processing applications. This flaw arises during the execution of scaling operations where input parameters derived from crafted or malformed video files are processed without adequate bounds checking or arithmetic validation. When an attacker supplies a specially constructed media file containing specific dimensions or frame rate values, the internal calculations responsible for allocating memory buffers and managing pixel data arrays exceed the maximum limit representable by the integer type used in the code logic. This overflow condition leads to incorrect allocation sizes, often resulting in significantly smaller buffer allocations than required for the actual video stream data.
From a technical perspective, this vulnerability is classified under CWE-190 Integer Overflow or Wraparound, which occurs when an arithmetic operation creates a number that is too large to be stored in the designated variable type. In the context of FFmpeg's scaling filter, the overflow typically manifests during the calculation of stride values or total buffer sizes needed for YUV or RGB pixel planes. Because the resulting integer wraps around to a small positive value, subsequent memory copy operations attempt to write data into an undersized heap region. This mismatch between expected and actual buffer capacity creates conditions ripe for out-of-bounds writes, which can corrupt adjacent memory structures, overwrite control flow data, or trigger immediate segmentation faults depending on the specific execution path and system architecture.
The operational impact of this vulnerability is primarily a Denial of Service against applications that utilize FFmpeg as their underlying multimedia framework. By triggering an integer overflow through a crafted video file, an attacker can cause the application to crash unexpectedly when attempting to process or decode the malicious input. This disruption affects services ranging from local media players and desktop editing software to server-side streaming platforms and cloud-based transcoding pipelines. The reliability of any system dependent on FFmpeg for real-time or batch video processing is compromised if such inputs are not sanitized, leading to service outages, loss of user data in progress, and potential instability in broader application ecosystems that rely on the library's core functionalities.
Mitigation strategies must focus on both immediate patching and long-term defensive coding practices. The primary remediation involves updating FFmpeg to a version where this specific integer overflow has been addressed by the development team through rigorous input validation and safe arithmetic checks before buffer allocation occurs. Developers integrating FFmpeg should ensure their build environments are configured to use the latest stable releases rather than arbitrary git commits unless necessary for feature access, as nightly builds may contain unpatched regressions. Furthermore, implementing runtime protection mechanisms such as Address Sanitizers during testing phases can help detect similar issues in custom code that interacts with libavfilter components.
In terms of industry standard mapping, this vulnerability aligns closely with CWE-190 for the integer overflow mechanism and CWE-787 Out-of-bounds Write if the overflow leads to memory corruption beyond simple crashes. From a tactical perspective within the MITRE ATT&CK framework, this flaw facilitates Initial Execution via crafted media files and contributes to Availability impact categories under Disrupt or Destroy operations. Security teams should treat such vulnerabilities as high-priority due to their ease of exploitation through standard file upload mechanisms common in web applications and content management systems that process user-uploaded video assets. Regular vulnerability scanning against known FFmpeg CVEs is essential for maintaining the integrity of multimedia processing infrastructure.