CVE-2026-106116 ImageSharp: BigTIFF IFD count can keep a decoder thread in a non-progressing loop
Attackers can cause a denial of service by forcing a decoder thread into an infinite loop using a malformed BigTIFF image.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-106116?
CVE-2026-106116 is a medium-severity denial of service 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, ExifReader.ReadValues64 trusts the 64-bit BigTIFF IFD entry count and iterates once per declared entry. When fewer than 20 bytes remain, ExifReader.ReadValue64 returns without advancing the stream or terminating the outer loop, so a small malformed BigTIFF can keep one decoder thread executing for an attacker-controlled duration. This report does not claim worker-pool exhaustion. This issue is fixed in version 4.1.2.
Weakness: CWE-835
Which versions are affected by CVE-2026-106116?
4 open source packages ship an affected version, including SixLabors.ImageSharp. It affects 1 product.
| Package | 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 include Sixlabors Imagesharp.
How do I fix CVE-2026-106116?
Upgrade SixLabors.ImageSharp to a fixed version for your release line: 3.2.0 or 4.1.2.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-106116 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-106116 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-2026-106115 ImageSharp: TIFF CCITT T6 encoder writes beyond an undersized output buffer
- CVE-2026-106117 ImageSharp: CCITT fax decompression (T4/Modified Huffman): unbounded WriteBits overflows strip buffer — heap OOB write in SixLabors.ImageSharp
Sources
Also known as ECHO-c871-d275-7ef9, GHSA-wmxv-xphr-5c9g.