# CVE-2026-106118: SixLabors ImageSharp TIFF heap overflow in tiled CCITT decompression

Source: https://junglewise.ai/threats/cve-2026-106118-imagesharp-is-a-2d-graphics-library-from-3-0-0-until-4-1-1-tiled  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-06. Updated: 2026-10-06  
License: CC BY 4.0 with a link back

CVE-2026-106118 · Severity: high · CVSS 7.5 · Published 2026-10-06

ImageSharp is a .NET graphics library used to process images in web applications and services. When processing specially crafted tiled TIFF files with fax compression, a width mismatch causes out-of-bounds writes into heap memory, potentially leading to data corruption, information disclosure, or crashing the application.

Technologies: [SixLabors ImageSharp](https://junglewise.ai/threats/technologies/imagesharp). Vendors: [NuGet](https://junglewise.ai/threats/vendors/nuget), [SixLabors](https://junglewise.ai/threats/vendors/sixlabors).

## Quick answers

**Is CVE-2026-106118 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-106118 being exploited in the wild.

**How severe is CVE-2026-106118?** High severity, with a CVSS score of 7.5, published 6 October 2026.

**Which products and versions are affected?** ImageSharp (NuGet) >= 3.0.0, < 4.1.1, ECOSYSTEM:introduced=3.0.0,fixed=4.1.1; SixLabors ImageSharp 3.0.0 to 4.1.0.

**Is there a fix for CVE-2026-106118?** Yes. ImageSharp (NuGet): upgrade to 4.1.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-106118 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-106118?** Check whether you run ImageSharp (NuGet) or SixLabors ImageSharp at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- ImageSharp (NuGet): upgrade to 4.1.1 or later

  ```sh
  dotnet add package ImageSharp --version 4.1.1
  ```


## Technical details

The vulnerability occurs in tiled TIFF decoding where TiffDecompressorsFactory creates CCITT decompressors (T4, T6, and Modified Huffman) using full frame width, but the destination buffer is allocated using tile width. This mismatch allows TiffDecoderCore.DecodeTilesChunky to direct full-width scanlines into a smaller tile-width buffer, causing out-of-bounds writes even with valid per-row run codes. The flaw is specific to the tiled path and distinct from strip-based CCITT vulnerabilities.

## Affected products

- SixLabors ImageSharp 3.0.0 to 4.1.0

## Identifiers

- CVE-2026-106118
- GHSA-v76p-62qx-wwq2

## Timeline

- 2026-10-06: disclosed
- 2026-08-20: patched

## References

- [https://github.com/SixLabors/ImageSharp/commit/9ee7d1dd5b62d8c9f16cc755e76828386bc2191f](https://github.com/SixLabors/ImageSharp/commit/9ee7d1dd5b62d8c9f16cc755e76828386bc2191f)
- [https://github.com/SixLabors/ImageSharp/pull/3176](https://github.com/SixLabors/ImageSharp/pull/3176)

## Related threats

- [ImageSharp buffer overflow in CCITT TIFF decompression](https://junglewise.ai/threats/cve-2026-106117-imagesharp-is-a-2d-graphics-library-from-3-0-0-until-4-1-1)
- [SixLabors ImageSharp denial of service in EXIF BigTIFF parser](https://junglewise.ai/threats/cve-2026-106116-imagesharp-is-a-2d-graphics-library-from-2-0-0-until-4-1-2)
- [ImageSharp TIFF CCITT Group 4 encoder buffer overflow](https://junglewise.ai/threats/cve-2026-106115-imagesharp-is-a-2d-graphics-library-from-2-1-0-until-4-1-2-the)
- [SixLabors ImageSharp ICC CLUT buffer over-allocation](https://junglewise.ai/threats/cve-2026-106114-imagesharp-is-a-2d-graphics-library-from-1-0-0-beta0001-until-4)
- [ImageSharp out-of-range access in histogram equalization](https://junglewise.ai/threats/cve-2026-106113-imagesharp-is-a-2d-graphics-library-from-2-0-0-until-4-1-2)