CVE-2026-106115 ImageSharp: TIFF CCITT T6 encoder writes beyond an undersized output buffer
Attacker-supplied TIFF images can trigger out-of-bounds writes in ImageSharp, causing memory corruption and potential code execution or crashes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-106115?
CVE-2026-106115 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 2.1.0 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.
Weakness: CWE-787
Which versions are affected by CVE-2026-106115?
4 open source packages ship an affected version, including SixLabors.ImageSharp. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
SixLabors.ImageSharp NuGet | From 2.1.0 | 3.2.0 |
SixLabors.ImageSharp NuGet | From 2.1.0 | 3.2.0 |
SixLabors.ImageSharp NuGet | From 4.0.0 | 4.1.2 |
SixLabors.ImageSharp NuGet | From 4.0.0 | 4.1.2 |
Products include Sixlabors Imagesharp.
How do I fix CVE-2026-106115?
Upgrade SixLabors.ImageSharp to a fixed version for your release line: 3.2.0 or 4.1.2.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-106115 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-106115 exists.
Other vulnerabilities in SixLabors ImageSharp
- CVE-2026-106110 ImageSharp: TIFF CCITT T4 encoder can write past its compressed output buffer
- CVE-2026-106112 ImageSharp: ICC LUT16 output channel count can write beyond Vector4
- CVE-2026-106113 ImageSharp: HistogramEqualization uses an unvalidated luminance as an unchecked histogram index
- CVE-2026-106117 ImageSharp: CCITT fax decompression (T4/Modified Huffman): unbounded WriteBits overflows strip buffer — heap OOB write in SixLabors.ImageSharp
- CVE-2025-27598 Out-of-bounds Write in SixLabors ImageSharp
Sources
Also known as ECHO-58f6-50c4-c97e, GHSA-jjfr-hcj7-qf5w.