CVE-2026-38348 in FFmpeg
Summary
by MITRE • 08/28/2026
An integer overflow in the libswscale/utils.c component of FFmpeg N-122528-gdd2976b9e1 allows attackers to cause a Denial of Service (DoS) via supplying a crafted image file.
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Analysis
by VulDB Data Team • 08/28/2026
The vulnerability identified as an integer overflow within the libswscale/utils.c component of FFmpeg represents a critical memory safety issue that can be exploited by malicious actors to disrupt service availability. This specific flaw resides in one of the core multimedia processing libraries utilized for video and audio scaling, which is widely embedded in numerous streaming platforms, media players, and content delivery networks. The root cause lies in the improper handling of arithmetic operations during image dimension calculations or buffer size estimations. When an attacker supplies a specially crafted image file with manipulated header values or metadata, the application performs integer addition or multiplication without adequate bounds checking. This results in an integer overflow where the calculated value wraps around to a significantly smaller number than intended due to fixed-width integer limitations.
From a technical perspective, this arithmetic error leads directly to incorrect memory allocation decisions. The software allocates a buffer based on the underflowed size rather than the actual required size for processing the image data. Subsequently, when the application attempts to write pixel data or perform scaling operations into this undersized buffer, it triggers a heap-based buffer overflow. This out-of-bounds write corrupts adjacent memory structures, potentially overwriting critical control data such as function pointers or object headers within the heap metadata. While the immediate reported impact is often categorized as a Denial of Service due to application crashes caused by segmentation faults or assertion failures triggered by corrupted state, this type of vulnerability inherently carries the risk of arbitrary code execution if an attacker can precisely manipulate memory layout and control flow redirection through careful exploitation techniques.
The operational impact of this vulnerability extends beyond simple service disruption for organizations relying on FFmpeg for automated media processing pipelines. In environments where untrusted content is ingested, such as user-generated video platforms or file upload services, attackers can leverage this flaw to crash the processing daemon repeatedly, leading to resource exhaustion and inability to serve legitimate requests. Furthermore, because libswscale is often linked statically into larger applications, the vulnerability affects a broad ecosystem of software products that depend on FFmpeg for image decoding and transformation tasks. The lack of robust input validation in older versions means that even seemingly innocuous image files can trigger this condition, making it an attractive target for automated scanning tools used by threat actors to identify vulnerable instances across the internet.
Mitigation strategies must prioritize immediate patching to a version of FFmpeg where this integer overflow has been addressed through rigorous bounds checking and safe arithmetic practices. Developers should ensure that all dimension parameters derived from external inputs are validated against maximum allowable limits before any memory allocation occurs. Additionally, implementing Address Space Layout Randomization (ASLR) and stack canaries in the deployment environment can provide essential layers of defense-in-depth to mitigate exploitation attempts even if the underlying vulnerability remains present for a short period until patches are applied. Security teams should also audit their media processing workflows to ensure that input sanitization is performed at the application layer, rejecting malformed files before they reach the vulnerable library functions.
This vulnerability aligns with Common Weakness Enumeration (CWE) identifiers such as CWE-190 Integer Overflow or Wraparound and CWE-787 Out-of-bounds Write, reflecting its nature as a memory corruption issue stemming from flawed arithmetic logic. In terms of tactical classification within the MITRE ATT&CK framework, this flaw facilitates Initial Access via Exploit Public-Facing Application if used to gain entry into a system, followed by Execution or Impact categories depending on whether code execution is achieved or only service disruption occurs. Understanding these mappings helps security professionals contextualize the risk and prioritize remediation efforts based on established industry standards for vulnerability management and secure coding practices.