CVE-2026-32882 libheif: Heap Buffer OOB Read in overlay compositing due to wrong alpha stride
A crafted HEIF file can trigger a heap buffer over-read in libheif, causing crashes or leaking adjacent memory during image compositing.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-32882?
CVE-2026-32882 is a high-severity memory corruption vulnerability in strukturag libheif, published on 19 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
libheif is a HEIF and AVIF file format decoder and encoder. Versions 1.21.2 and prior contain a heap buffer over-read in HeifPixelImage::overlay() in libheif/pixelimage.cc. When compositing an overlay image (iovl) whose child image has a different bit depth for the alpha channel than for the color channels, the function indexes into the alpha plane using the color channel stride (in_stride) instead of the previously retrieved alpha_stride, causing reads past the end of the alpha buffer (up to 3,123 bytes for a 100×50 image with 10-bit color and 8-bit alpha). A crafted HEIF file can exploit this to cause a denial of service (crash) or potentially disclose adjacent heap memory through leaked bytes embedded in the decoded output pixels. This issue has been fixed in versionThis issue has been fixed in version 1.22.0.
Weakness: CWE-125
Which versions are affected by CVE-2026-32882?
How do I fix CVE-2026-32882?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-32882 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-32882 exists.
Sources
Also known as BELL-CVE-2026-32882, DEBIAN-CVE-2026-32882, ECHO-480e-f2af-bd01, GHSA-hg7q-rjr2-8x46, ROOT-OS-DEBIAN-11-CVE-2026-32882, ROOT-OS-DEBIAN-12-CVE-2026-32882 and 1 more.