strukturag libheif up to 1.21.x AVIF File create_clone_image_at_new_size information disclosure

Summaryinfo

A vulnerability identified as problematic has been detected in strukturag libheif up to 1.21.x. The impacted element is the function create_clone_image_at_new_size of the component AVIF File Handler. This manipulation causes information disclosure. This vulnerability appears as CVE-2026-32814. The attack may be initiated remotely. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in strukturag libheif up to 1.21.x. It has been declared as problematic. Affected by this vulnerability is the function create_clone_image_at_new_size of the component AVIF File Handler. The manipulation with an unknown input leads to a information disclosure vulnerability. The CWE definition for the vulnerability is CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. As an impact it is known to affect confidentiality. The summary by CVE is:

libheif is a HEIF and AVIF file format decoder and encoder. In versions 1.21.2 and prior, when decoding a HEIF grid image with strict_decoding=false (the default), a corrupted tile silently fails to decode and the library returns heif_error_Ok with no indication of failure, leading to an uninitialized heap memory information leak. The canvas is allocated via create_clone_image_at_new_size() → plane.alloc() → new (std::nothrow) uint8_t[allocation_size] which does not zero the memory; only the alpha plane is explicitly initialized via fill_plane(), so the Y, Cb, and Cr planes contain whatever was previously at that heap address. The failed tile's region of the canvas is never written. It retains uninitialized heap data that is delivered to the caller as decoded pixel values (4,096 bytes per Y/Cb/Cr plane = 12,288+ bytes total). Any application using libheif to decode grid-based HEIF/AVIF files with default settings is vulnerable: a crafted .heic or .avif file causes 4,096+ bytes of heap memory to appear as pixel values in the decoded image, and the calling application receives heif_error_Ok, so it has no indication the output contains heap garbage. In server-side image processing, an uploaded crafted HEIF decoded and re-encoded (e.g., as PNG/JPEG for thumbnails, CDN, social media) can leak cross-user data such as auth tokens, database results, and other users' image data. This issue has been fixed in version 1.22.0.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-32814 since 03/16/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1592 according to MITRE ATT&CK.

The vulnerability scanner Nessus provides a plugin with the ID 316399 (Linux Distros Unpatched Vulnerability : CVE-2026-32814), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.22.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (316399). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Vendor

• strukturag

Name

• libheif

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10
• 1.11
• 1.12
• 1.13
• 1.14
• 1.15
• 1.16
• 1.17
• 1.18
• 1.19
• 1.20
• 1.21

Website

• Product: https://github.com/strukturag/libheif/

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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