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 Vector Local

Attack Complexity Low

Privileges Required None

Attack Requirements Present

User Interaction Passive

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Local

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact High

Availability Impact High

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
saitoha libsixel unaffected
Version Status Constraints
0 affected < 1.8.7-r1
1.9.0 affected ≤ 1.10.5

No data.

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Project Subscriptions

Vendors Products
Saitoha Subscribe
Libsixel Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/libsixel/libsixel/blob/v1.10.5/src/fromgif.c#L219-L240 cve-icon cve-icon
https://github.com/saitoha/libsixel/blob/v1.8.7/src/fromgif.c#L182-L248 cve-icon cve-icon
https://github.com/saitoha/libsixel/commit/bdbab09816eb9188429c37a50b97c5e66dfe5047 cve-icon cve-icon
https://github.com/saitoha/libsixel/issues/220 cve-icon cve-icon
https://github.com/saitoha/libsixel/releases/tag/v1.8.7-r1 cve-icon cve-icon
https://hackmd.io/@haind-pwn/libsixel-gif-transparent-index-oob-write cve-icon cve-icon
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 cve-icon cve-icon
History

Wed, 14 Oct 2026 14:30:00 +0000

Type Values Removed Values Added
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.
Title libsixel before 1.8.7-r1 and 1.9.0 through 1.10.5 Heap Out-of-Bounds Write via GIF
First Time appeared Saitoha
Saitoha libsixel
Weaknesses CWE-787
CPEs cpe:2.3:a:saitoha:libsixel:*:*:*:*:*:*:*:*
Vendors & Products Saitoha
Saitoha libsixel
References
Metrics cvssV3_1

{'score': 6.3, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H'}

cvssV4_0

{'score': 5.8, 'vector': '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'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-14T14:16:43.022Z

Reserved: 2026-10-14T13:07:20.557Z

Link: CVE-2026-110601

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-14T15:17:11.530

Modified: 2026-10-14T15:17:11.530

Link: CVE-2026-110601

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses