Out-of-bounds Read in Strukturag Libheif

CVE-2026-84449

libheif is a HEIF and AVIF file format decoder and encoder. Prior to 1.19.6, Op_RGB24_32_to_YCbCr::convert_colorspace() stores image-plane strides in an integer width that can overflow for extremely large RGB images created through heif_image_create() and heif_image_add_plane(). The resulting wrapped stride causes the conversion loop in libheif/color-conversion/rgb2yuv.cc to compute an invalid input pointer and read beyond the allocated interleaved plane while heif_context_encode_image() performs RGB-to-YCbCr conversion. This can crash the encoding process. This issue is fixed in version 1.19.6.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 3.7 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L.

EPSS exploit prediction

EPSS: 0.004 (36.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 36.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-84449: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: -0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-84449?
CVE-2026-84449 is a low-severity vulnerability in Strukturag Libheif, classified under Out-of-bounds Read. CVSS score: 3.7/10. Published 2026-09-18.
How severe is CVE-2026-84449?
Low severity. CVSS v3 base score is 3.7 out of 10.