Medium severity · published Oct 14, 2026
CVE-2026-110601
libsixel before 1.8.7-r1 and 1.9.0 through 1.10.5 Heap Out-of-Bounds Write via GIF
6.3
CVSS
0.2%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H
Attack vector
Local
Complexity
High
Privileges
None
User interaction
Required
Confidentiality
None
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 15% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
libsixel · saitoha
before 1.8.7-r1; 1.9.0 through 1.10.5 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-110601
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-110601
issue-tracking
https://github.com/saitoha/libsixel/issues/220
patch
https://github.com/saitoha/libsixel/commit/bdbab09816eb9188429c37a50b97c5e66dfe5047
release-notes
https://github.com/saitoha/libsixel/releases/tag/v1.8.7-r1
technical-description
https://github.com/saitoha/libsixel/blob/v1.8.7/src/fromgif.c#L182-L248
technical-description
https://github.com/libsixel/libsixel/blob/v1.10.5/src/fromgif.c#L219-L240
third-party-advisory
https://hackmd.io/@haind-pwn/libsixel-gif-transparent-index-oob-write
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