CVE-2026-56363

What it actually does

ImageMagick versions before 7.1.2-22 contain an arithmetic error in binomial kernel processing. A crafted image-processing request or command that supplies an excessively large binomial kernel value can trigger integer overflow, which then leads to division by zero and process termination. The impact is availability only: the vulnerable ImageMagick process can crash, but the provided details do not indicate code execution, data disclosure, or privilege escalation.

Why it matters to the business

Systems, applications, or workflows that use ImageMagick to process untrusted or user-supplied images may experience service interruptions if a malicious or malformed input causes the image-processing worker to crash. The CVSS score is low and EPSS is very low, it is not listed in CISA KEV, and no public exploit maturity is reported, so broad exploitation is not currently indicated; however, exposed upload, conversion, thumbnailing, or media-processing pipelines should still be patched to avoid preventable outages.

How an attack unfolds

An attacker first identifies an application or job that invokes ImageMagick on attacker-controlled content or parameters, such as an image upload, conversion API, batch-processing queue, or command-line workflow. The attacker then submits input or processing instructions that cause ImageMagick to evaluate a binomial kernel with an overly large value. In vulnerable versions before 7.1.2-22, that value can overflow during kernel calculation and produce a division-by-zero condition. The ImageMagick process then crashes, interrupting the current operation and potentially degrading service if the application does not isolate workers, retry safely, or rate-limit repeated submissions. Exploitation requires user interaction in the CVSS assessment and currently has no reported mature exploit or KEV listing.

How to fix it

Upgrade ImageMagick to version 7.1.2-22 or later wherever ImageMagick 7.x is installed. If ImageMagick is supplied by an operating-system package manager, apply the vendor security update once available and verify the installed package includes the upstream fix. For containers and embedded runtimes, rebuild images so the patched ImageMagick binary and libraries are present. As interim mitigation, avoid passing untrusted user input into ImageMagick kernel parameters, restrict or sanitize image-processing options, isolate image-processing workers with process supervisors, memory/CPU limits, and timeouts, and rate-limit upload or conversion endpoints that invoke ImageMagick.

How to confirm the fix worked

Confirm the installed ImageMagick version is 7.1.2-22 or later using `magick -version` or the platform package manager. Validate that application containers and worker images have been rebuilt and are not still carrying older ImageMagick binaries or shared libraries. Review application code and job definitions to ensure user-controlled input cannot directly set unsafe kernel parameters. In a controlled non-production environment, run regression tests for image upload, conversion, resize, thumbnail, and morphology/convolution workflows and confirm crafted malformed inputs fail safely without crashing the service process.

Typical attack path

1. Find an application, service, or workflow that uses ImageMagick for image manipulation or conversion.
2. Determine whether attacker-controlled files or image-processing options can reach ImageMagick binomial kernel processing.
3. Submit crafted input using an excessively large binomial kernel value.
4. Trigger integer overflow during binomial kernel calculation.
5. Cause division by zero and crash the ImageMagick process.
6. Repeat submissions to create sustained denial of service if the surrounding application automatically retries or exposes the vulnerable path repeatedly.

How to detect it

Look for evidence of prior exploitation by correlating application requests or queued image-processing jobs with ImageMagick worker crashes. Relevant sources include web access logs for upload/conversion endpoints, application logs that record ImageMagick command arguments or job parameters, worker supervisor logs, container runtime logs, system logs, crash dumps, core dump metadata, and endpoint telemetry. Focus on repeated crashes of `magick`, `convert`, or ImageMagick-linked worker processes shortly after processing user-submitted content, especially where logs include binomial kernel, morphology, or convolution parameters. Search for SIGFPE, floating-point exception, arithmetic exception, division-by-zero, abnormal exits, core dumps, or container restarts associated with ImageMagick. Since the vulnerability causes denial of service rather than persistence or code execution, likely artifacts are crash and request patterns rather than malware files or long-lived host indicators.

• Binomial:
• binomial kernel
• -morphology
• Convolve
• SIGFPE
• Floating point exception
• division by zero
• Arithmetic exception
• core dumped
• magick
• convert
• ImageMagick
• exited with signal 8
• signal 8
• exit code 136

What your security team should do

• Inventory applications, containers, CI images, and batch jobs that invoke ImageMagick, especially those handling user-supplied images or conversion requests.
• Prioritize upgrading exposed upload, media-processing, thumbnailing, document-conversion, and API-backed image manipulation services to ImageMagick 7.1.2-22 or later.
• Rebuild and redeploy container images or statically packaged applications that bundle ImageMagick rather than relying only on host package updates.
• Add input validation so external users cannot control ImageMagick kernel names, kernel sizes, or morphology/convolution parameters.
• Run ImageMagick workloads in isolated worker processes with resource limits, crash restart controls, queue backoff, and rate limiting to reduce denial-of-service impact.
• Monitor for repeated ImageMagick crashes, SIGFPE events, division-by-zero messages, or suspicious use of binomial kernel options in application logs and job payloads.
• Because EPSS is very low, not KEV-listed, and no mature exploit is reported, handle as routine patching unless ImageMagick is internet-facing or used in critical high-volume processing pipelines.