CVE-2026-33855: Android-ImageMagick7 Integer Overflow

CVE-2026-33855 Overview

CVE-2026-33855 is an Integer Overflow or Wraparound vulnerability affecting MolotovCherry Android-ImageMagick7, a popular Android port of the ImageMagick image processing library. This vulnerability allows remote attackers to cause a denial of service condition by exploiting improper handling of integer calculations within the image processing routines. The issue affects all versions of Android-ImageMagick7 prior to version 7.1.2-11.

Critical Impact

Remote attackers can exploit this integer overflow vulnerability to cause application crashes and denial of service on Android devices using vulnerable versions of Android-ImageMagick7.

Affected Products

• MolotovCherry Android-ImageMagick7 versions prior to 7.1.2-11

Discovery Timeline

• 2026-03-24 - CVE-2026-33855 published to NVD
• 2026-03-26 - Last updated in NVD database

Technical Details for CVE-2026-33855

Vulnerability Analysis

This vulnerability stems from an Integer Overflow or Wraparound condition (CWE-190) in the Android-ImageMagick7 library. Integer overflow vulnerabilities occur when arithmetic operations attempt to create numeric values that exceed the maximum representable value for the data type, causing the value to wrap around to an unexpected result.

In the context of image processing libraries like ImageMagick, integer overflows are particularly dangerous as they often occur during calculations related to image dimensions, buffer sizes, or pixel data processing. When an attacker supplies a specially crafted image with malicious dimension values or metadata, the overflow can lead to incorrect memory allocation sizes, which subsequently causes crashes or other undefined behavior.

The network-based attack vector indicates that this vulnerability can be exploited remotely by having a target application process a malicious image file retrieved from a network source. No user interaction or authentication is required, making this vulnerability accessible to unauthenticated remote attackers.

Root Cause

The root cause of CVE-2026-33855 is improper handling of integer arithmetic operations within the Android-ImageMagick7 codebase. When processing image data, calculations involving dimensions, pixel counts, or buffer sizes can exceed the maximum value of the integer data type, resulting in wraparound to a small or negative number. This leads to undersized memory allocations that cannot accommodate the actual image data being processed.

Attack Vector

The attack exploits the network-accessible nature of image processing operations. An attacker can craft a malicious image file containing specially designed dimension values or metadata that triggers the integer overflow during processing. When the vulnerable Android-ImageMagick7 library attempts to parse or render this image, the overflow condition causes memory corruption or allocation failures, resulting in application denial of service.

The attack sequence typically involves:

1. Creating a malicious image with crafted dimension values designed to cause integer overflow
2. Delivering the malicious image to the target application via network (web download, messaging, email attachment)
3. The vulnerable application processes the image using Android-ImageMagick7
4. Integer overflow occurs during size calculations, leading to crash or denial of service

For technical details on the vulnerability and fix implementation, refer to the GitHub Pull Request #187.

Detection Methods for CVE-2026-33855

Indicators of Compromise

• Unexpected application crashes when processing image files from untrusted sources
• Memory allocation failures or out-of-memory conditions during image rendering
• Abnormal resource consumption patterns in applications using Android-ImageMagick7

Detection Strategies

• Monitor application crash reports for segmentation faults or memory access violations related to image processing operations
• Implement logging for image processing operations to identify malformed or suspicious image files
• Deploy application performance monitoring to detect unusual memory allocation patterns
• Review dependency manifests to identify applications using vulnerable Android-ImageMagick7 versions

Monitoring Recommendations

• Enable crash reporting and analytics for applications utilizing Android-ImageMagick7
• Implement file validation checks for images received from external sources before processing
• Monitor for repeated application restarts or service disruptions that may indicate exploitation attempts

How to Mitigate CVE-2026-33855

Immediate Actions Required

• Update Android-ImageMagick7 to version 7.1.2-11 or later immediately
• Review all applications and projects using Android-ImageMagick7 as a dependency
• Consider implementing input validation for image files before processing with ImageMagick
• Deploy application sandboxing to limit the impact of potential exploitation

Patch Information

The vulnerability has been addressed in Android-ImageMagick7 version 7.1.2-11. The fix involves proper bounds checking and safe integer arithmetic to prevent overflow conditions during image processing operations. For detailed patch information, refer to the GitHub Pull Request #187.

Workarounds

• Validate image file dimensions and metadata before processing with Android-ImageMagick7
• Implement resource limits (memory, processing time) for image processing operations
• Reject images with unusually large or suspicious dimension values
• Consider using image processing in a sandboxed environment to contain potential crashes

# Update Android-ImageMagick7 dependency in build.gradle
# Replace vulnerable version with patched version 7.1.2-11 or later
implementation 'com.github.MolotovCherry:Android-ImageMagick7:7.1.2-11'