CVE-2026-48029 in libheif
Summary
by MITRE • 07/22/2026
libheif is a HEIF and AVIF file format decoder and encoder. Versions 1.19.0 through 1.21.2 have a heap OOB read in ImageItem_Grid::decode_grid_tile via irot-induced tile-coordinate underflow. Version 1.22.0 fixes the issue.
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Analysis
by VulDB Data Team • 07/22/2026
The vulnerability resides within libheif, a widely-used library for handling HEIF and AVIF image formats that serves as both decoder and encoder for these modern image standards. This heap out-of-bounds read affects versions between 1.19.0 and 1.21.2, specifically when processing ImageItem_Grid::decode_grid_tile operations that involve irot (image rotation) induced tile-coordinate underflow conditions. The flaw manifests when the library processes grid-based image compositions where individual tiles are arranged in a structured layout, and rotational transformations are applied to these tiles during decoding operations.
The technical implementation of this vulnerability stems from inadequate input validation and boundary checking within the grid tile coordinate calculation logic. When irot parameters are processed, the system fails to properly validate or clamp coordinate values that could result in negative indices when accessing heap-allocated memory regions. This underflow condition causes the application to read memory locations that lie outside the intended buffer boundaries, potentially exposing sensitive data or creating opportunities for further exploitation. The vulnerability falls under CWE-129, which addresses improper validation of array indices, and more specifically aligns with CWE-787, which covers out-of-bounds write operations that can result from improper input validation.
The operational impact of this vulnerability extends across numerous applications that rely on libheif for image processing, including web browsers, mobile operating systems, content management systems, and digital asset processing platforms. Attackers could potentially exploit this issue by crafting malicious HEIF or AVIF files with specifically designed grid structures and rotational parameters that trigger the underflow condition. The out-of-bounds read could expose memory contents from adjacent heap allocations, potentially revealing sensitive information such as cryptographic keys, session tokens, or other application data stored in memory. This vulnerability represents a significant concern for systems processing untrusted image content, as it can be leveraged to extract confidential information through carefully constructed file formats.
Mitigation strategies should prioritize immediate upgrade to libheif version 1.22.0 or later, which includes the necessary patches to address the coordinate underflow issue. Security-conscious organizations should also implement input validation measures that restrict the range of acceptable grid parameters and rotational values during image processing operations. Additionally, deploying runtime protections such as address space layout randomization and heap integrity checking can help mitigate potential exploitation scenarios. The vulnerability demonstrates the importance of proper boundary checking in multimedia format processing libraries, particularly those handling complex structured data formats like HEIF and AVIF that support advanced features such as grid layouts and rotational transformations. Organizations should conduct thorough testing to ensure their applications properly handle malformed image files and implement defensive programming practices to prevent similar issues in other components that process structured binary data.
This vulnerability also aligns with several ATT&CK techniques including T1059 for execution through file format processing, and T1203 for exploitation of memory corruption vulnerabilities. The remediation approach should include comprehensive code review of input validation mechanisms and implementation of automated testing for edge cases in grid-based image processing workflows.