CVE-2026-110601
libsixel before 1.8.7-r1 and 1.9.0 through 1.10.5 Heap Out-of-Bounds Write via GIF
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.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
5.8
libsixel before 1.8.7-r1 and 1.9.0 through 1.10.5 Heap Out-of-Bounds Write via GIF
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.
- Record
CVE-2026-110601- CVSS 4.0
- 5.8 Medium
CVSS: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
- 6.3 Medium
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H - Weakness
- CWE-787
- Updated
- 2026-11-02
EUVDEUVD-2026-101229
5.8
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.
- Record
EUVD-2026-101229- CVSS 4.0
- 5.8 Medium
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-5j3r-7cc6-965h
5.8
libsixel before 1.8.7-r1 and 1.9.0 through 1.10.5 contains a heap out-of-bounds write...
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.
- Record
GHSA-5j3r-7cc6-965h- CVSS 4.0
- 5.8 Medium
CVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 6.3 Medium
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H - Weakness
- CWE-787
- Updated
- 2026-11-02
NVD
5.8
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.
- Record
CVE-2026-110601- CVSS 4.0
- 5.8 Medium
CVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 6.3 Medium
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H - Weakness
- CWE-787
- Updated
- 2026-11-02
OSV
5.8
libsixel before 1.8.7-r1 and 1.9.0 through 1.10.5 Heap Out-of-Bounds Write via GIF
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.
- Record
CVE-2026-110601- CVSS 4.0
- 5.8 Medium
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N - Weakness
- CWE-787
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-110601
5.8
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.
- Record
DEBIAN-CVE-2026-110601- CVSS 4.0
- 5.8 Medium
CVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-110601
5.8
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.
- Record
UBUNTU-CVE-2026-110601- CVSS 4.0
- 5.8 Medium
CVSS: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
- 6.3 Medium
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
libsixelDebian:12 |
All versions, plus listed versions 1.10.3-31.10.5-11:1.8.7-11:1.8.7-21:1.8.7-3 Show 4 moreShow less1:1.8.7-41:1.8.7-51:1.8.7-61:1.8.7-r2-1 |
None known |
libsixelDebian:13 |
All versions, plus listed versions 1.10.5-11:1.8.7-11:1.8.7-21:1.8.7-31:1.8.7-41:1.8.7-51:1.8.7-61:1.8.7-r2-1 |
None known |
libsixelDebian:14 |
before 1:1.8.7-r2-1, plus listed versions 1.10.5-11:1.8.7-11:1.8.7-21:1.8.7-31:1.8.7-41:1.8.7-51:1.8.7-6 |
1:1.8.7-r2-1 |
libsixelUbuntu:16.04:LTS |
All versions, plus listed versions 1.4.2-11.5.2-2 |
None known |
libsixelUbuntu:18.04:LTS |
All versions, plus listed versions 1.5.2-21.7.3-1 |
None known |
libsixelUbuntu:20.04:LTS |
All versions, plus listed versions 1.8.2-11.8.2-2.1 |
None known |
libsixelUbuntu:22.04:LTS |
All versions, plus listed versions 1.8.6-21.10.3-21.10.3-3 |
None known |
libsixelUbuntu:24.04:LTS |
All versions, plus listed versions 1.10.3-31.10.3-3build1 |
None known |
libsixelUbuntu:26.10 |
All versions, plus listed versions 1.10.5-1build11:1.8.7-r2-1 |
None known |
libsixelUbuntu:26.04:LTS |
All versions, plus listed versions 1.10.5-11.10.5-1build1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-110601 is a medium vulnerability (CVSS 5.8) in Saitoha Libsixel, published October 14, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.24%, the 14th percentile. Fixed in libsixel 1:1.8.7-r2-1.
References
github.com/saitoha/libsixel/issues/220
github.com/saitoha/libsixel/commit/bdbab09816eb9188429c37a50b97c5e66dfe5047
github.com/saitoha/libsixel/releases/tag/v1.8.7-r1
github.com/saitoha/libsixel/blob/v1.8.7/src/fromgif.c
github.com/libsixel/libsixel/blob/v1.10.5/src/fromgif.c
hackmd.io/@haind-pwn/libsixel-gif-transparent-index-oob-write
Show 9 moreShow less
vulncheck.com/advisories/libsixel-before-1.8.7-r1-and-1.9.0-through-1.10.5-heap-out-of-bounds-write-via-gif
nvd.nist.gov/vuln/detail/CVE-2026-110601
github.com/advisories/GHSA-5j3r-7cc6-965h
github.com
github.com/CVEProject/cvelistV5/tree/main/cves/2026/110xxx/CVE-2026-110601.json
github.com/saitoha/libsixel
security-tracker.debian.org/tracker/CVE-2026-110601
ubuntu.com/security/CVE-2026-110601
cve.org/CVERecord?id=CVE-2026-110601