# CVE-2026-106113: ImageSharp: HistogramEqualization uses an unvalidated luminance as an unchecked histogram index

> Attackers can cause a denial of service by supplying a malicious TIFF image that triggers an out-of-bounds memory access during histogram equalization.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 6 Oct 2026
- **Updated:** 7 Oct 2026
- **Also known as:** ECHO-abbf-6840-ed40, GHSA-j3p4-wp97-rph4

## What is CVE-2026-106113?

CVE-2026-106113 is a high-severity memory corruption vulnerability in SixLabors ImageSharp, published on 6 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

ImageSharp is a 2D graphics library. From 2.0.0 until 4.1.2, decoding an attacker-supplied 32-bit floating-point TIFF as Image<HalfVector4> and applying HistogramEqualization can produce a non-finite or out-of-range luminance in ColorNumerics.GetBT709Luminance. GrayscaleLevelsRowOperation.Invoke uses the resulting value as an unchecked histogram offset, causing an unsafe out-of-range access and process termination. Adaptive Histogram Equalization and AutoLevel are not affected by this report. This issue is fixed in version 4.1.2.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-106113?

4 open source packages ship an affected version, including SixLabors.ImageSharp. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `SixLabors.ImageSharp` | NuGet | From 2.0.0 | 3.2.0 |
| `SixLabors.ImageSharp` | NuGet | From 2.0.0 | 3.2.0 |
| `SixLabors.ImageSharp` | NuGet | From 4.0.0 | 4.1.2 |
| `SixLabors.ImageSharp` | NuGet | From 4.0.0 | 4.1.2 |

Products: Sixlabors Imagesharp.

## How do I fix CVE-2026-106113?

Upgrade SixLabors.ImageSharp to a fixed version for your release line: 3.2.0 or 4.1.2.

## Is CVE-2026-106113 being exploited?

There is no known exploitation of CVE-2026-106113 in the wild and no public exploit code.

## Other vulnerabilities in SixLabors ImageSharp

- [CVE-2026-106110](https://insights.sbomify.com/CVE-2026-106110/): ImageSharp: TIFF CCITT T4 encoder can write past its compressed output buffer (high 7.5)
- [CVE-2026-106112](https://insights.sbomify.com/CVE-2026-106112/): ImageSharp: ICC LUT16 output channel count can write beyond Vector4 (high 7.5)
- [CVE-2026-106115](https://insights.sbomify.com/CVE-2026-106115/): ImageSharp: TIFF CCITT T6 encoder writes beyond an undersized output buffer (high 7.5)
- [CVE-2026-106117](https://insights.sbomify.com/CVE-2026-106117/): ImageSharp: CCITT fax decompression (T4/Modified Huffman): unbounded WriteBits overflows strip buffer — heap OOB write in SixLabors.ImageSharp (high 7.5)
- [CVE-2025-27598](https://insights.sbomify.com/CVE-2025-27598/): Out-of-bounds Write in SixLabors ImageSharp (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-106113 and fix it if it is affected.

What it is: CVE-2026-106113 is a high-severity memory corruption vulnerability in SixLabors ImageSharp, published on 6 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-106113 in the wild and no public exploit code.

Affected packages and fixed versions:
- SixLabors.ImageSharp (NuGet): affected from 2.0.0; fixed in 3.2.0
- SixLabors.ImageSharp (NuGet): affected from 2.0.0; fixed in 3.2.0
- SixLabors.ImageSharp (NuGet): affected from 4.0.0; fixed in 4.1.2
- SixLabors.ImageSharp (NuGet): affected from 4.0.0; fixed in 4.1.2

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-106113/ (Markdown: https://insights.sbomify.com/CVE-2026-106113/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-106113
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-106113
- OSV: https://osv.dev/vulnerability/CVE-2026-106113

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-106113/
Summaries are generated and may contain mistakes; the official description above is the record.