Is CVE-2026-118747 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-118747 being exploited in the wild.

How severe is CVE-2026-118747?

High severity, with a CVSS score of 7.5, published 10 November 2026.

Which products and versions are affected?

System.Formats.Cbor (NuGet) >= 8.0.0-0, < 8.0.2, ECOSYSTEM:introduced=8.0.0-0,fixed=8.0.2.

Is there a fix for CVE-2026-118747?

Yes. System.Formats.Cbor (NuGet): upgrade to 8.0.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-118747 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-118747?

Check whether you run Microsoft .Net or System.Formats.Cbor (NuGet) 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.

CVE-2026-118747: .NET inefficient algorithmic complexity denial of service

Q: Is there a fix for CVE-2026-118747?

Yes. System.Formats.Cbor (NuGet): upgrade to 8.0.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-118747 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-118747?

Check whether you run Microsoft .Net or System.Formats.Cbor (NuGet) 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.

CVE-2026-118747 · Severity: high · CVSS 7.5 · Published 2026-11-10

.NET is a widely-used platform for building enterprise applications. An algorithmic complexity flaw allows an attacker to send specially crafted network requests that consume excessive CPU and memory, causing the application to become unresponsive and denying service to legitimate users.

Technologies: Microsoft .Net. Vendors: Microsoft, NuGet.

Quick answers

Is CVE-2026-118747 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-118747 being exploited in the wild.
How severe is CVE-2026-118747?: High severity, with a CVSS score of 7.5, published 10 November 2026.
Which products and versions are affected?: System.Formats.Cbor (NuGet) >= 8.0.0-0, < 8.0.2, ECOSYSTEM:introduced=8.0.0-0,fixed=8.0.2.
Is there a fix for CVE-2026-118747?: Yes. System.Formats.Cbor (NuGet): upgrade to 8.0.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-118747 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-118747?: Check whether you run Microsoft .Net or System.Formats.Cbor (NuGet) 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

System.Formats.Cbor (NuGet): upgrade to 8.0.2 or later

dotnet add package System.Formats.Cbor --version 8.0.2

Technical details

An inefficient algorithmic complexity vulnerability exists in .NET's processing logic, exploitable remotely without authentication. An attacker can craft specific inputs that trigger worst-case algorithmic behavior, consuming disproportionate system resources and causing denial of service. The vulnerability does not require user interaction or special network positioning.

Affected products

Microsoft .NET

Identifiers

CVE-2026-118747
GHSA-vmv3-wvjp-wqpj

Timeline

2026-11-10: disclosed

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-118747

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