Out-of-Bounds Write in SixLabors.ImageSharp (CVE-2026-106112)
Summary
Out-of-bounds write in SixLabors.ImageSharp (CVE-2026-106112). Risk of unauthorized operations or information disclosure. Exploitable via Vector4. Mitigation: upgrade to 4.1.2 or later.
Original description
The description as published by the source.
Summary
When ICC conversion is enabled, a malformed embedded ICC LUT16 profile with
more than four output channels can corrupt memory during ImageSharp color
conversion. The ICC parser accepts up to 15 CLUT output channels, while the
conversion implementation stores intermediate values in Vector4.
Affected package and versions
- Package:
SixLabors.ImageSharp(NuGet) - Affected published releases: 4.0.0, 4.1.0, and 4.1.1
- Affected range:
>= 4.0.0, <= 4.1.1 - Commit
0815358f9202a78bc7f3b83e19282dc3654b500fcorresponds to release v4.1.1.
The reproduced ColorProfileHandling.Convert path and the unsafe Vector4 LUT operations are present in v4.0.0 and unchanged through v4.1.1. The three-output control succeeds on all three published 4.x releases; the fifteen-output exploit terminates all three.
Details
IccClut accepts one through fifteen input and output channels. In the
reproduced A2B0 LUT16 path, an attacker-controlled profile declares three
input channels and fifteen output channels. ClutCalculator.Calculate
passes a pointer to a four-float Vector4 result into interpolation code that
writes one float per declared output channel. It consequently writes fifteen
floats. The same LUT16 tag also has fifteen output LUTs; their
[LutEntryCalculator.CalculateLut](https://github.com/…
Source: NIST National Vulnerability Database 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-2026-106112 has been found in SixLabors.ImageSharp.
Attackers can target a specific entry point like Vector4 over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: upgrade SixLabors.ImageSharp to 4.1.2 or later.
If unsure, ask your IT team or search "SixLabors.ImageSharp CVE-2026-106112" on the vendor's site.
CVE-2026-106112 (SixLabors.ImageSharp) — CWE-787 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: Vector4 / SixLabors.ImageSharp / ColorProfileHandling.Convert / IccClut
Patched: 4.1.2 — apply immediately
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 SixLabors.ImageSharp. Attackers reach the vulnerable code path via Vector4 without authentication.
Check the vendor advisory for the affected versions of SixLabors.ImageSharp. Attack surface: Vector4 / SixLabors.ImageSharp / ColorProfileHandling.Convert / IccClut.
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.
Update to 4.1.2.
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 'SixLabors.ImageSharp' . 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 'SixLabors.ImageSharp' . | 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
SixLabors.ImageSharpを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade SixLabors.ImageSharp to 4.1.2ステージング環境で 4.1.2 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-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。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com
- web github.com
- web github.com