CVE-2026-84448: CWE-125: Out-of-bounds Read in strukturag libheif
libheif is a HEIF and AVIF file format decoder and encoder. Prior to 1.23.2, the public heif_region_item_add_region_inline_mask_data() function in libheif/api/libheif/heif_regions.cc accepts mask_data_len without verifying that it equals the byte count required by width and height. A later heif_region_get_mask_image() call derives the read length from the region geometry, so an undersized stored buffer causes heif_region_get_inline_mask_image() to read beyond the heap allocation and copy adjacent bytes into the returned monochrome mask image. This can disclose heap data or crash an application that constructs region metadata through the writer API, while the file-parsing path is not affected because it validates the canonical mask size. This issue is fixed in version 1.23.2.
AI Analysis
Technical Summary
The vulnerability in strukturag libheif (CVE-2026-84448) involves an out-of-bounds read (CWE-125) caused by improper validation of mask_data_len in the heif_region_item_add_region_inline_mask_data() function. When mask_data_len is smaller than the required byte count derived from the region's width and height, subsequent calls to heif_region_get_inline_mask_image() read beyond the allocated heap buffer. This can lead to disclosure of adjacent heap memory or application crashes when region metadata is constructed via the writer API. The file-parsing path is unaffected because it validates the mask size correctly. The vulnerability is resolved in version 1.23.2 of libheif.
Potential Impact
An attacker could cause an out-of-bounds read leading to disclosure of adjacent heap memory or cause an application crash. This affects applications that construct region metadata using the writer API of libheif. The file parsing functionality is not vulnerable. The CVSS 3.1 base score is 4.0 (medium severity), reflecting limited impact with local attack vector, high attack complexity, no privileges required, no user interaction, and partial confidentiality impact.
Mitigation Recommendations
Upgrade to libheif version 1.23.2 or later, where this vulnerability is fixed. No other mitigations are indicated. Since this is a library vulnerability, ensure that all dependent applications update their libheif dependency accordingly.
CVE-2026-84448: CWE-125: Out-of-bounds Read in strukturag libheif
Description
libheif is a HEIF and AVIF file format decoder and encoder. Prior to 1.23.2, the public heif_region_item_add_region_inline_mask_data() function in libheif/api/libheif/heif_regions.cc accepts mask_data_len without verifying that it equals the byte count required by width and height. A later heif_region_get_mask_image() call derives the read length from the region geometry, so an undersized stored buffer causes heif_region_get_inline_mask_image() to read beyond the heap allocation and copy adjacent bytes into the returned monochrome mask image. This can disclose heap data or crash an application that constructs region metadata through the writer API, while the file-parsing path is not affected because it validates the canonical mask size. This issue is fixed in version 1.23.2.
CVSS v3.1
Score 4.0medium
Affected software
strukturag
libheif
pkg:github/strukturag/libheifRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in strukturag libheif (CVE-2026-84448) involves an out-of-bounds read (CWE-125) caused by improper validation of mask_data_len in the heif_region_item_add_region_inline_mask_data() function. When mask_data_len is smaller than the required byte count derived from the region's width and height, subsequent calls to heif_region_get_inline_mask_image() read beyond the allocated heap buffer. This can lead to disclosure of adjacent heap memory or application crashes when region metadata is constructed via the writer API. The file-parsing path is unaffected because it validates the mask size correctly. The vulnerability is resolved in version 1.23.2 of libheif.
Potential Impact
An attacker could cause an out-of-bounds read leading to disclosure of adjacent heap memory or cause an application crash. This affects applications that construct region metadata using the writer API of libheif. The file parsing functionality is not vulnerable. The CVSS 3.1 base score is 4.0 (medium severity), reflecting limited impact with local attack vector, high attack complexity, no privileges required, no user interaction, and partial confidentiality impact.
Mitigation Recommendations
Upgrade to libheif version 1.23.2 or later, where this vulnerability is fixed. No other mitigations are indicated. Since this is a library vulnerability, ensure that all dependent applications update their libheif dependency accordingly.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-09-01T20:05:09.423Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6aad608d55bf5e2cf5360fa2
Added to database: 09/18/2026, 16:02:21 UTC
Last enriched: 09/18/2026, 16:17:44 UTC
Last updated: 09/19/2026, 01:01:44 UTC
Views: 7
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