CVE-2026-110601 libsixel before 1.8.7-r1 and 1.9.0 through 1.10.5 Heap Out-of-Bounds Write via GIF
Attackers can trigger heap corruption or crashes in libsixel by supplying a crafted GIF with an invalid transparent color index.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-110601?
CVE-2026-110601 is a medium-severity memory corruption vulnerability in saitoha libsixel, published on 14 Oct 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
libsixel before 1.8.7-r1 and 1.9.0 through 1.10.5 contains a heap out-of-bounds write vulnerability in gif_init_frame() in src/fromgif.c, which never checks the GIF transparent color index against the palette size. Attackers can supply a crafted GIF with a small color table and large transparent index, processed with a background color set, to write bytes past the palette buffer, causing heap corruption or crashes.
Weakness: CWE-787
Which versions are affected by CVE-2026-110601?
How do I fix CVE-2026-110601?
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-2026-110601 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-110601 exists.
Sources
Also known as DEBIAN-CVE-2026-110601, GHSA-5j3r-7cc6-965h, UBUNTU-CVE-2026-110601.