Patch Forecast
Amber warning
Patch this week.

CVE-2026-106115 · GHSA-jjfr-hcj7-qf5w

ImageSharp: TIFF CCITT T6 encoder writes beyond an undersized output buffer

Risk score
66/100
CVSS
7.5 v3.1
Exploit chance (30 days)
0.4%
Published
6 Oct 2026

Open in the live forecast Today's forecast

What to know

What it is
ImageSharp is a 2D graphics library. From 2.1.0 until 4.1.2, the TIFF CCITT Group 4 encoder allocates Width times rowsPerStrip bytes even though T6BitCompressor.CompressStrip can emit encoded row data and two 12-bit end-of-facsimile-block codes beyond that capacity. TiffCcittCompressor.WriteCode performs unchecked wri…
Affected
SixLabors.ImageSharp (nuget) >= 2.1.0, <= 4.1.1
Fix
Upgrade SixLabors.ImageSharp to 4.1.2 or later.
Exploitation
Public proof of concept

Story map

Story map: SixLabors.ImageSharpTHE FLAWSTHE FIXCVE-2026-106115ImageSharp: TIFF CCITT T6encoder writes beyond anundersized output bufferCVSS 7.5 · EPSS 0%CVE-2026-106112ImageSharp: ICC LUT16 outputchannel count can write beyondVector4CVSS 7.5 · EPSS 0%CVE-2026-106110ImageSharp: TIFF CCITT T4encoder can write past itscompressed output bufferCVSS 7.5 · EPSS 0%CVE-2026-106113ImageSharp:HistogramEqualization uses anunvalidated luminance as an…CVSS 7.5 · EPSS 0%Upgrade…4.1.2or later on your release lineWho is exposedSixLabors.ImageSharp (nuget)>= 2.1.0, <= 4.1.1AMBER · PATCH THIS WEEKSixLabors.ImageSharpImageSharp is a 2D graphicslibrary. From 2.1.0 until 4.1.2,the TIFF CCITT Group 4encoder allocates Width timesrowsPerStrip bytes even thoughT6BitCompressor.CompressStrip can emit encoded row data…Where it standsPublic proof of conceptCONNECTS TOSame weaknessOut-of-bounds write (CWE-787)255 other warnings in 30 days →Same productEarlier SixLabors.ImageSharp warnings3 in the last 90 days →
Story map: the flaws, the fix, how it unfolded and what it connects to. Boxes link to the record or article.

At a glance

SixLabors.ImageSharp: Amber, patch this week. ImageSharp is a 2D graphics library. From 2.1.0 until 4.1.2, the TIFF CCITT Group 4 encoder allocates Width times rowsPerStrip bytes even though T6BitCompressor.CompressStrip can emit encoded row data and two 12-bit end-of-facsimile-block codes beyond that capacity. TiffCcittCompressor.WriteCode performs unchecked wri…

The flaws

  • CVE-2026-106115: ImageSharp: TIFF CCITT T6 encoder writes beyond an undersized output buffer (CVSS 7.5 · EPSS 0%)
  • CVE-2026-106112: ImageSharp: ICC LUT16 output channel count can write beyond Vector4 (CVSS 7.5 · EPSS 0%)
  • CVE-2026-106110: ImageSharp: TIFF CCITT T4 encoder can write past its compressed output buffer (CVSS 7.5 · EPSS 0%)
  • CVE-2026-106113: ImageSharp: HistogramEqualization uses an unvalidated luminance as an unchecked histogram index (CVSS 7.5 · EPSS 0%)

The fix

Upgrade SixLabors.ImageSharp: 4.1.2 or later on your release line

Who is exposed: SixLabors.ImageSharp (nuget) >= 2.1.0, <= 4.1.1

Where it stands

  • Public proof of concept

Connects to

Why it is Amber

  • CVSS 7.5 high
  • Public exploit or proof of concept referenced
  • Remotely exploitable without logging in
  • On your watchlist: NuGet

Affected packages

PackageEcosystemVulnerableFixed in
SixLabors.ImageSharpnuget>= 2.1.0, <= 4.1.14.1.2

References

Original description

ImageSharp is a 2D graphics library. From 2.1.0 until 4.1.2, the TIFF CCITT Group 4 encoder allocates Width times rowsPerStrip bytes even though T6BitCompressor.CompressStrip can emit encoded row data and two 12-bit end-of-facsimile-block codes beyond that capacity. TiffCcittCompressor.WriteCode performs unchecked writes, and a decode-and-re-encode flow can inherit TiffCompression.CcittGroup4Fax and one-bit metadata from attacker-supplied input. The resulting out-of-bounds writes can corrupt memory and terminate the process. This issue is fixed in version 4.1.2.

Last activity 6 Oct 2026. Patch Forecast updates every hour.