CVE-2026-49271 libheif: Wrapped icef compressed-unit range check causes out-of-bounds read in uncompressed HEIF decoder
A crafted HEIF file triggers an integer overflow in libheif, causing an out-of-bounds read and application crash.
- 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-2026-49271?
CVE-2026-49271 is a medium-severity vulnerability in strukturag libheif, published on 19 Jun 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. Prior to version 1.22.1, the uncompressed HEIF decoder validates explicit icef compressed-unit offsets using unit_offset + unit_size. Because the addition can wrap, a crafted HEIF file can pass the range check and then construct a vector from iterators outside the compressed item buffer, producing an out-of-bounds heap read and crash. Version 1.22.1 patches the issue.
Weakness: CWE-125
Which versions are affected by CVE-2026-49271?
It affects 1 product.
Products include Struktur Libheif.
How do I fix CVE-2026-49271?
Upgrade to a fixed version.
Is CVE-2026-49271 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-49271 exists.
Other vulnerabilities in strukturag libheif
Sources
Also known as BELL-CVE-2026-49271, DEBIAN-CVE-2026-49271, ECHO-77c2-91a0-4936, GHSA-r7qj-cg5r-r6vf, JLSEC-2026-1101, MINI-fvjp-p586-mvf2 and 1 more.