# CVE-2026-106118: ImageSharp: Tiled fax TIFF: tile buffer sized by TileWidth but fax decompressor writes scanlines of ImageWidth — heap OOB write

> Attacker can trigger heap out-of-bounds writes via crafted tiled TIFF files, leading to code execution or crashes in applications using ImageSharp.

- **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:** 6 Oct 2026
- **Also known as:** ECHO-9c96-4e24-b0b3, GHSA-v76p-62qx-wwq2

## What is CVE-2026-106118?

CVE-2026-106118 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 3.0.0 until 4.1.1, tiled TIFF decoding allocates a destination buffer using TileWidth but TiffDecompressorsFactory.Create constructs T4, T6, and Modified Huffman decompressors using the full frame width. TiffDecoderCore.DecodeTilesChunky can therefore direct frame-width fax scanlines into a tile-width buffer when TileWidth is smaller than ImageWidth. The mismatch causes attacker-controlled out-of-bounds writes, heap corruption, and process termination even with legal per-row run codes. This tiled-path vulnerability is distinct from oversized CCITT runs in strip decoding. This issue is fixed in version 4.1.1.

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

## Which versions are affected by CVE-2026-106118?

4 open source packages ship an affected version, including SixLabors.ImageSharp.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `SixLabors.ImageSharp` | NuGet | From 3.0.0 | 3.2.0 |
| `SixLabors.ImageSharp` | NuGet | From 3.0.0 | 3.2.0 |
| `SixLabors.ImageSharp` | NuGet | From 4.0.0 | 4.1.1 |
| `SixLabors.ImageSharp` | NuGet | From 4.0.0 | 4.1.1 |

## How do I fix CVE-2026-106118?

Upgrade SixLabors.ImageSharp to a fixed version for your release line: 3.2.0 or 4.1.1.

## Is CVE-2026-106118 being exploited?

There is no known exploitation of CVE-2026-106118 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-106118 and fix it if it is affected.

What it is: CVE-2026-106118 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-2026-106118 in the wild and no public exploit code.

Affected packages and fixed versions:
- SixLabors.ImageSharp (NuGet): affected from 3.0.0; fixed in 3.2.0
- SixLabors.ImageSharp (NuGet): affected from 3.0.0; fixed in 3.2.0
- SixLabors.ImageSharp (NuGet): affected from 4.0.0; fixed in 4.1.1
- SixLabors.ImageSharp (NuGet): affected from 4.0.0; fixed in 4.1.1

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-2026-106118/ (Markdown: https://insights.sbomify.com/CVE-2026-106118/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-106118
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-106118
- OSV: https://osv.dev/vulnerability/CVE-2026-106118

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-106118/
Summaries are generated and may contain mistakes; the official description above is the record.