Out-of-Bounds Write in libsixel (CVE-2026-110601)
Summary
Out-of-bounds write in libsixel (CVE-2026-110601). Data can be tampered with by attackers.
Original description
The description as published by the source.
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.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-110601 has been found in libsixel.
Data can be tampered with by attackers. CVSS score: 6.3/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "libsixel CVE-2026-110601" on the vendor's site.
CVE-2026-110601 (libsixel) — CWE-787 / CVSS v3 6.3
Attack vector: local / unauthenticated
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Out-of-bounds write (CWE-787) exists in libsixel.
Check the vendor advisory for the affected versions of libsixel.
Severity: Medium (CVSS 6.3/10). Data can be tampered with by attackers.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'libsixel' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'libsixel' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
libsixelを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。