CVE-2026-109263 in ImageMagick
Summary
by MITRE • 10/12/2026
ImageMagick before 6.9.13-57 and 7.x before 7.1.2-32 contains a memory leak in the YUV encoder, which fails to release allocated memory when a specific operation fails. Attackers can supply crafted input that triggers the failing encoder operation, leaking memory and potentially exhausting resources to cause a denial of service.
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Analysis
by VulDB Data Team • 10/12/2026
The vulnerability identified in ImageMagick versions prior to 6.9.13-57 and 7.x prior to 7.1.2-32 represents a critical resource management flaw within the YUV image encoding subsystem. This defect is classified under CWE-401, which denotes a missing release of memory after effective use, leading to potential resource exhaustion. The core technical issue stems from improper error handling logic embedded in the encoder routines responsible for processing YUV color space data. When the library attempts to encode an image into the YUV format, it allocates specific buffers and temporary structures required for pixel manipulation and conversion operations. Under normal circumstances, these allocations are properly freed upon successful completion of the encoding task. However, if a specific condition triggers a failure within this process—such as encountering malformed data or unsupported parameters—the code path fails to execute the necessary deallocation commands. This oversight results in allocated memory blocks remaining resident in the system heap even after the operation has terminated abnormally.
From an operational perspective, this flaw allows for a remote denial of service attack vector that does not require authentication if ImageMagick is configured to process untrusted image uploads automatically. An attacker can craft specific input files designed to trigger the failing encoder path repeatedly. Each successful exploitation attempt results in a small but measurable amount of memory being leaked from the application's address space. While individual leaks may appear negligible, their cumulative effect over time leads to progressive degradation of system performance and eventual service unavailability as available RAM is consumed by orphaned allocations. This behavior aligns with ATT&CK technique T1498, Network Denial of Service, specifically through resource exhaustion via application-level vulnerabilities rather than network bandwidth saturation. The impact extends beyond simple availability loss; in environments where ImageMagick processes high volumes of images, such as content management systems or photo hosting platforms, the rapid consumption of server resources can cause cascading failures affecting other services running on the same host.
Mitigation strategies primarily involve upgrading to patched versions that correct the error handling logic within the YUV encoder module. For organizations unable to immediately patch their infrastructure due to dependency constraints, implementing strict input validation and size limits for uploaded images serves as an effective compensating control. Additionally, deploying resource monitoring tools that detect abnormal memory growth patterns in ImageMagick processes can provide early warning indicators of exploitation attempts. It is also advisable to restrict the use of ImageMagick's command-line utilities like convert or magick to only trusted local files rather than exposing them via web interfaces without rigorous sanitization layers. Ensuring that the underlying operating system employs memory limits and container isolation further mitigates the blast radius should an attacker succeed in triggering repeated leaks, thereby preserving overall system stability despite the application-level vulnerability.