CVE-2026-32741
7.1
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H
Exploitability: 2.8 / Impact: 4.2
Source: security-advisories@github.com (Secondary)
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.
Related CWEs
CWE-120
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow.
CWE-122
Heap-based Buffer Overflow
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
References (6)
Source: security-advisories@github.com
Source: security-advisories@github.com
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Timeline
No history available yet.