CVE-2026-30929: 
C# vulnerability analysis and mitigation

CVE-2026-30929 is a stack-based buffer overflow vulnerability in the MagnifyImage function of ImageMagick, a widely used open-source image editing library. The vulnerability arises because MagnifyImage uses a fixed-size stack buffer that can be overflowed when processing a specially crafted image, leading to stack corruption. It affects ImageMagick versions prior to 6.9.13-41 and 7.0.0-0 through 7.1.2-15, as well as Magick.NET NuGet packages prior to version 14.10.4. The vulnerability was published on March 9–10, 2026, and carries a CVSS v3.1 base score of 7.7–7.8 (High) (GitHub Advisory, ImageMagick Advisory).

The root cause is a stack-based buffer overflow (CWE-121) combined with an out-of-bounds write (CWE-787) in the MagnifyImage function, which allocates a fixed-size buffer on the stack without adequate bounds checking. An attacker can trigger the overflow by supplying a maliciously crafted image file to any application that invokes MagnifyImage during image processing. The attack vector is local (AV:L) with low complexity and no privileges required, meaning any user who can supply an image to the affected process can trigger the vulnerability. The vulnerability was reported by researcher ThePwnish3r (ImageMagick Advisory, GitHub Advisory).

Successful exploitation can result in stack corruption, leading to application crashes (denial of service) and potential memory integrity violations. The CVSS scoring reflects high integrity and high availability impacts with no confidentiality impact, meaning an attacker could corrupt data or crash the ImageMagick process but direct data disclosure is not the primary concern. In environments where ImageMagick processes untrusted images (e.g., web applications, media pipelines), exploitation could disrupt service availability or potentially be leveraged for further code execution depending on memory layout (GitHub Advisory, ImageMagick Advisory).

1. Craft a malicious image: Create or obtain a specially crafted image file (e.g., a malformed TIFF, PNG, or other format supported by ImageMagick) designed to trigger the fixed-size stack buffer overflow in the MagnifyImage function when the image dimensions or pixel data cause the buffer to be exceeded.
2. Deliver the image: Supply the crafted image to a target system running a vulnerable version of ImageMagick (prior to 7.1.2-16 or 6.9.13-41). This could be via a local file, an upload to a web application that processes images, or any pipeline invoking convert, magick, or a library call that triggers MagnifyImage.
3. Trigger processing: Invoke ImageMagick's magnify/resize operation on the crafted image (e.g., convert malicious.png -magnify output.png), causing MagnifyImage to write beyond the fixed-size stack buffer.
4. Achieve stack corruption: The overflow corrupts adjacent stack memory, potentially overwriting return addresses or control data, leading to a crash (DoS) or, under favorable memory layout conditions, arbitrary code execution in the context of the ImageMagick process (ImageMagick Advisory).

• Process: Unexpected crashes or segmentation faults in ImageMagick processes (convert, magick, or applications embedding libMagickCore); core dump files generated in working directories.
• Logs: Application logs showing ImageMagick terminating abnormally (e.g., signal 11/SIGSEGV or signal 6/SIGABRT) when processing specific image files; repeated processing failures on the same input file.
• File System: Presence of unusual or malformed image files (oversized, unexpected format headers, or anomalous pixel data) in upload directories or image processing queues.
• Network: In web application contexts, repeated upload requests of the same or similarly structured image files from a single source IP, particularly targeting image magnification or resize endpoints.

Update ImageMagick to version 7.1.2-16 or later (7.x branch) or 6.9.13-41 or later (6.9.x branch). For Magick.NET users, upgrade to 14.10.4 or later. If immediate patching is not possible, restrict access to ImageMagick processing functionality, validate and sanitize all image inputs from untrusted sources, and consider sandboxing the ImageMagick process (e.g., using seccomp, AppArmor, or running in a container with limited privileges) to contain the impact of potential exploitation. Debian, Amazon Linux 2, openSUSE, and other distributions have released updated packages (GitHub Advisory, ImageMagick Advisory).

The vulnerability received routine coverage from security aggregators and Linux distribution security teams, including Debian, Amazon Linux 2, openSUSE, and SUSE, all of which issued updated packages. Tenable published multiple Nessus detection plugins (IDs 301752, 304613, 305282, 309923, and others) to identify vulnerable installations. No notable researcher commentary or significant social media discussion beyond standard CVE tracking has been observed.