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The vulnerability, identified as CVE-2026-30931, is a heap-based buffer overflow found in the UHDR encoder of ImageMagick. The issue stems from the truncation of a value during image processing, which leads to an undersized memory buffer being allocated on the heap. When the image data is subsequently written to this insufficiently sized buffer, it causes an out-of-bounds write. This memory corruption can lead to a denial of service by crashing the application. In specific scenarios, this overflow might be exploited further to achieve arbitrary code execution, although it is primarily considered a moderate severity issue due to the complexity of such exploitation. The vulnerability is present in versions prior to 7.1.2-16 .
dailycve form:
Platform: ImageMagick
Version: < 7.1.2-16
Vulnerability : Heap Buffer Overflow
Severity: Moderate
Date: March 9, 2026
Prediction: Patched (Mar 12, 2026)
What Undercode Say:
Analytics:
The vulnerability is rooted in improper integer handling. The function responsible for writing UHDR images truncates a value, leading to a heap-based buffer overflow. To analyze or test for this vulnerability, one can use the following methods:
1. Check Version: Determine if your installed version is vulnerable.
identify -version | grep Version
If the version is below 7.1.2-16, it is likely affected.
2. Static Analysis (Conceptual): The vulnerable code pattern in `coders/uhdr.c` would resemble a calculation for buffer size that can be truncated, followed by a write operation that does not check the new, smaller bounds.
3. Dynamic Analysis with Sanitizers: To detect this overflow at runtime, compile ImageMagick with AddressSanitizer and process a crafted UHDR image. The output would show a heap-buffer-overflow error, similar to the one identified during discovery:
==1575126==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7fc382ef3820 WRITE of size 8 at 0x7fc382ef3820 thread T0
This output confirms an out-of-bounds write attempt .
- System Log Monitoring: Monitor system logs for crashes related to ImageMagick, which may indicate a denial-of-service attempt.
journalctl | grep -i "imagemagick|core dump" | tail -20
Exploit:
The exploitation vector is through a specially crafted image file. An attacker would create a UHDR image with specific, large dimensions or properties that trigger the integer truncation during the encode process. When ImageMagick attempts to process this file (e.g., using the `convert` or `identify` command, or through an automated service), the flawed arithmetic calculates a buffer that is too small. The subsequent write operation then overflows this buffer, corrupting adjacent heap memory. While the primary impact is a crash (denial of service), a sophisticated attacker might manipulate the heap layout to turn this overflow into arbitrary code execution .
Protection from this CVE:
The primary mitigation is to update to a patched version.
1. Update ImageMagick: Upgrade to version 7.1.2-16 or later.
For Debian/Ubuntu sudo apt update && sudo apt upgrade imagemagick For RHEL/CentOS/Fedora sudo yum update ImageMagick or sudo dnf update ImageMagick
2. Input Validation: If an immediate update is not possible, avoid processing UHDR images from untrusted sources. Implement strict validation on image dimensions and file sizes before passing them to ImageMagick .
3. Policy File Restriction: Use ImageMagick’s policy.xml file to restrict the resources or coders that can be used, potentially disabling the UHDR coder if it is not required for your operations.
<!-- Example snippet to disable UHHR coder in policy.xml --> <policy domain="coder" rights="none" pattern="UHDR" />
Impact:
Successful exploitation of this vulnerability can lead to a denial of service, causing the application using ImageMagick to crash. In more severe cases, it could potentially allow an attacker to execute arbitrary code with the privileges of the user running ImageMagick, leading to system compromise or data breach. The integrity of the system is at risk if code execution is achieved, and a loss of availability is almost certain .
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Sources:
Reported By: github.com
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