libheif has a heap buffer overflow in decode_mask_image()_CVE-2026-32741

7.1 / 10

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H

Description

libheif is a HEIF and AVIF file format decoder and encoder. Versions 1.21.2 and below contain a heap buffer overflow in MaskImageCodec::decode_mask_image(). When decoding a HEIF file containing a mask image (mski), the function copies the full iloc extent data into a pixel buffer using memcpy(dst, data.data(), data.size()). The copy length data.size() is determined by the iloc extent in the file (attacker-controlled), while the destination buffer is sized based on the declared image dimensions. Because no upper-bound check exists on the data length, a crafted file whose iloc extent exceeds the pixel buffer allocation overflows the heap. The vulnerable single-memcpy branch is reached when the mskC property specifies bits_per_pixel = 8 and the ispe property declares an even width ≥ 64 (so that stride == width), with no changes to default security limits or external codec plugins required. This issue has been fixed in version 1.22.0.

Basic Information

ID CVE-2026-32741

Source GitHub_M

Published May 19, 2026 at 19:57

Affected Product

Vendor strukturag

Product libheif

Version < 1.22.0

Affected Versions strukturag libheif < 1.22.0

CWE Classification

CWE-122

References

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    "published": "2026-05-19T19:57:26.525Z",
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