CVE-2026-53462: ImageMagick Use-After-Free Vulnerability

CVE-2026-53462 Overview

CVE-2026-53462 is a heap use-after-free vulnerability [CWE-416] in ImageMagick, the open-source image editing and manipulation library. The flaw resides in the CheckPrimitiveExtent function. When a memory allocation fails inside this routine, ImageMagick continues to reference freed heap memory, leading to a crash. The issue affects ImageMagick versions prior to 6.9.13-50 and 7.1.2-25. Maintainers patched the defect in releases 6.9.13-50 and 7.1.2-25. The vulnerability is reachable over the network when an application processes attacker-supplied image or drawing primitives through ImageMagick.

Critical Impact

Remote attackers can trigger a process crash by submitting crafted input that forces an allocation failure inside CheckPrimitiveExtent, resulting in denial of service for applications relying on ImageMagick.

Affected Products

• ImageMagick versions prior to 6.9.13-50
• ImageMagick 7.x versions prior to 7.1.2-25
• Applications and services that embed vulnerable ImageMagick builds for image processing

Discovery Timeline

• 2026-06-10 - CVE-2026-53462 published to NVD
• 2026-06-10 - Last updated in NVD database

Technical Details for CVE-2026-53462

Vulnerability Analysis

The vulnerability is a heap use-after-free condition in the CheckPrimitiveExtent function within ImageMagick's drawing primitive handling code. CheckPrimitiveExtent is responsible for ensuring that the primitive buffer used during vector drawing operations has sufficient capacity. When this function attempts to grow the buffer and the underlying allocation fails, the error path does not correctly invalidate pointers that still reference the previously freed memory region. Subsequent code paths then dereference these dangling pointers.

An attacker who can supply a crafted image, MVG file, or drawing command sequence to a service that uses ImageMagick can engineer conditions that cause the allocation to fail. The resulting access of freed memory produces undefined behavior, most commonly a crash. The CVSS vector reflects high attack complexity because the attacker must shape memory pressure or input sizes that reliably trigger the failing allocation path. The impact is limited to availability, with no confidentiality or integrity compromise reported.

Root Cause

The root cause is improper error handling in CheckPrimitiveExtent. The function frees or reallocates the primitive buffer but leaves stale references in caller scope when the allocation step fails. This violates the invariant that pointers to reallocated buffers must be refreshed or nullified along every exit path.

Attack Vector

Exploitation occurs over the network. An adversary submits a malformed or oversized drawing primitive, MVG document, or image containing vector instructions to an application that invokes ImageMagick. The processing pipeline reaches CheckPrimitiveExtent, fails the allocation, and then operates on freed memory. The vulnerability does not require authentication or user interaction. The realistic outcome is a denial-of-service crash of the worker process or hosting service.

No verified public proof-of-concept is available. See the GitHub Security Advisory GHSA-px7q-ggqj-hcf2 for upstream technical details.

Detection Methods for CVE-2026-53462

Indicators of Compromise

• Unexpected segmentation faults or SIGABRT events from processes invoking ImageMagick binaries such as convert, magick, or mogrify.
• Core dumps with stack frames referencing CheckPrimitiveExtent or surrounding drawing primitive routines.
• Repeated upload of unusually large or malformed MVG, SVG, or image files to web endpoints that perform server-side image processing.

Detection Strategies

• Inventory all ImageMagick installations and compare installed versions against 6.9.13-50 and 7.1.2-25 using package manager queries or magick -version.
• Enable application crash logging and forward journalctl, Windows Error Reporting, or container runtime exit signals to centralized telemetry for correlation.
• Inspect web application logs for HTTP 5xx spikes coinciding with image uploads to identify probing attempts.

Monitoring Recommendations

• Monitor child process exit codes from image-processing workers and alert on abnormal termination rates.
• Track resource consumption of ImageMagick worker pools to identify allocation-failure patterns consistent with exploitation attempts.
• Audit ingress paths that accept user-supplied images and log file metadata, MIME type, and size for forensic review.

How to Mitigate CVE-2026-53462

Immediate Actions Required

• Upgrade ImageMagick to version 6.9.13-50 or 7.1.2-25 or later across all affected systems, containers, and base images.
• Rebuild and redeploy applications that statically link or vendor ImageMagick libraries.
• Restrict ingestion of user-supplied MVG and SVG content until patched builds are deployed.

Patch Information

The ImageMagick project addressed the issue in versions 6.9.13-50 and 7.1.2-25. The upstream fix corrects the error handling in CheckPrimitiveExtent so that the function safely propagates allocation failures without leaving dangling references. Refer to the ImageMagick Security Advisory GHSA-px7q-ggqj-hcf2 for the patched commits and release notes.

Workarounds

• Disable or restrict use of drawing primitives and MVG processing in policy.xml for deployments that cannot patch immediately.
• Enforce strict size and resource limits on memory, map, area, and disk policies to reduce attacker control over allocation pressure.
• Run ImageMagick in a sandboxed worker process with automatic restart so a crash does not propagate denial of service to the parent application.

# Example /etc/ImageMagick-7/policy.xml hardening
<policymap>
  <policy domain="coder" rights="none" pattern="MVG" />
  <policy domain="coder" rights="none" pattern="SVG" />
  <policy domain="resource" name="memory" value="256MiB" />
  <policy domain="resource" name="map" value="512MiB" />
  <policy domain="resource" name="area" value="128MB" />
  <policy domain="resource" name="disk" value="1GiB" />
</policymap>