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. 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

5.8CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

6.3CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H

EPSS

0.2% chance of exploitation in the next 30 days; higher than 14% of CVEs (scores of 2026-10-25)

CWE

CWE-787

Published

2026-10-14

Modified

2026-10-20

Record from

the NVD, synced 2026-10-21

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

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