CVE-2026-110601
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.
Does this matter?
Lower severity and a low EPSS score (0.24%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 4.0
- 5.8 MEDIUMCVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.24% probability · 14th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-787
- Source
- disclosure@vulncheck.com
EPSS moved from 0.2% on 15 October 2026 to 0.2% on 26 October 2026.
References
- https://github.com/libsixel/libsixel/blob/v1.10.5/src/fromgif.c#L219-L240
- https://github.com/saitoha/libsixel/blob/v1.8.7/src/fromgif.c#L182-L248
- https://github.com/saitoha/libsixel/commit/bdbab09816eb9188429c37a50b97c5e66dfe5047
- https://github.com/saitoha/libsixel/issues/220
- https://github.com/saitoha/libsixel/releases/tag/v1.8.7-r1
- https://hackmd.io/@haind-pwn/libsixel-gif-transparent-index-oob-write
- https://www.vulncheck.com/advisories/libsixel-before-1.8.7-r1-and-1.9.0-through-1.10.5-heap-out-of-bounds-write-via-gif
- https://github.com/saitoha/libsixel/issues/220
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.