Recorded 16 Oct 2026 at 16:13 UTC. This is what ChangeIntel recorded, including the title, summary, facts and links. It is not a statement of the source's current position.
See the latest record.
The historical field “Public exploit code” recorded Nuclei detection-template membership. It did not establish exploit availability. The original recorded fields remain below.
CVEMicrosoft Security Response Center
MessagePack-CSharp Denial of Service Vulnerability
Improperly controlled sequential memory allocation in .NET allows an unauthorized attacker to deny service over a network.
Microsoft Edge (Chromium-based), Microsoft Visual Studio 2022 version 17.14, Microsoft Visual Studio 2026 version 18.10, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Linux, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Mac OS, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Windows, System.Formats.Cbor on .NET 10.0 installed on Linux, System.Formats.Cbor on .NET 10.0 installed on Mac OS, System.Formats.Cbor on .NET 10.0 installed on Windows, System.Formats.Cbor on .NET 8.0 installed on Linux, System.Formats.Cbor on .NET 8.0 installed on Mac OS, System.Formats.Cbor on .NET 8.0 installed on Windows, System.Formats.Cbor on .NET 9.0 installed on Linux, System.Formats.Cbor on .NET 9.0 installed on Mac OS, System.Formats.Cbor on .NET 9.0 installed on Windows
Updates that fix it
No KB listed
CISA KEV
Not listed in the collected catalog
EPSS
Not scored
Public exploit code
No Nuclei template listed
Published
13 Oct 2026 07:00 UTC
Last revised
15 Oct 2026 07:00 UTC
Revision note
Updated the Security Updates table to add KB article links for .NET 11.0. This is an informational change only; the fixed builds are unchanged.
Complete at observationRead 16 Oct 2026 at 16:12 UTC
CISA KEV
Complete at observationRead 16 Oct 2026 at 16:12 UTC
FIRST EPSS
Complete at observationRead 16 Oct 2026 at 16:12 UTC
Public detection templates (Nuclei)
Complete at observationRead 16 Oct 2026 at 16:12 UTC
Coverage describes the sources at this observation. A complete read then does not establish their current position.
What changed
Affected products: MessagePack 2.5.303, Microsoft Visual Studio 2022 version 17.14, Microsoft Visual Studio 2026 version 18.10, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Linux, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Mac OS, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Windows, System.Formats.Cbor on .NET 10.0 installed on Linux, System.Formats.Cbor on .NET 10.0 installed on Mac OS, System.Formats.Cbor on .NET 10.0 installed on Windows, System.Formats.Cbor on .NET 8.0 installed on Linux, System.Formats.Cbor on .NET 8.0 installed on Mac OS, System.Formats.Cbor on .NET 8.0 installed on Windows, System.Formats.Cbor on .NET 9.0 installed on Linux, System.Formats.Cbor on .NET 9.0 installed on Mac OS, System.Formats.Cbor on .NET 9.0 installed on Windows → Microsoft Edge (Chromium-based), Microsoft Visual Studio 2022 version 17.14, Microsoft Visual Studio 2026 version 18.10, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Linux, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Mac OS, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Windows, System.Formats.Cbor on .NET 10.0 installed on Linux, System.Formats.Cbor on .NET 10.0 installed on Mac OS, System.Formats.Cbor on .NET 10.0 installed on Windows, System.Formats.Cbor on .NET 8.0 installed on Linux, System.Formats.Cbor on .NET 8.0 installed on Mac OS, System.Formats.Cbor on .NET 8.0 installed on Windows, System.Formats.Cbor on .NET 9.0 installed on Linux, System.Formats.Cbor on .NET 9.0 installed on Mac OS, System.Formats.Cbor on .NET 9.0 installed on Windows
Publisher revision note: Information published. → Updated the Security Updates table to add KB article links for .NET 11.0. This is an informational change only; the fixed builds are unchanged. · Affected products: MessagePack 2.5.303, Microsoft Visual Studio 2022 version 17.14, Microsoft Visual Studio 2026 version 18.10, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 10.0 installed on Linux, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 10.0 installed on Mac OS, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 10.0 installed on Windows, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Linux, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Mac OS, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Windows, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 8.0 installed on Linux, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 8.0 installed on Mac OS, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 8.0 installed on Windows, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 9.0 installed on Linux, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 9.0 installed on Mac OS, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 9.0 installed on Windows → MessagePack 2.5.303, Microsoft Visual Studio 2022 version 17.14, Microsoft Visual Studio 2026 version 18.10, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Linux, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Mac OS, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Windows, System.Formats.Cbor on .NET 10.0 installed on Linux, System.Formats.Cbor on .NET 10.0 installed on Mac OS, System.Formats.Cbor on .NET 10.0 installed on Windows, System.Formats.Cbor on .NET 8.0 installed on Linux, System.Formats.Cbor on .NET 8.0 installed on Mac OS, System.Formats.Cbor on .NET 8.0 installed on Windows, System.Formats.Cbor on .NET 9.0 installed on Linux, System.Formats.Cbor on .NET 9.0 installed on Mac OS, System.Formats.Cbor on .NET 9.0 installed on Windows
Page history
Changes are dated when recorded; day views use the last saved version from that UTC day, and citations stay fixed.
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16 Oct 2026 · 16:13:25 UTCAffected productsMessagePack 2.5.303, Microsoft Visual Studio 2022 version 17.14, Microsoft Visual Studio 2026 version 18.10, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Linux, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Mac OS, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Windows, System.Formats.Cbor on .NET 10.0 installed on Linux, System.Formats.Cbor on .NET 10.0 installed on Mac OS, System.Formats.Cbor on .NET 10.0 installed on Windows, System.Formats.Cbor on .NET 8.0 installed on Linux, System.Formats.Cbor on .NET 8.0 installed on Mac OS, System.Formats.Cbor on .NET 8.0 installed on Windows, System.Formats.Cbor on .NET 9.0 installed on Linux, System.Formats.Cbor on .NET 9.0 installed on Mac OS, System.Formats.Cbor on .NET 9.0 installed on Windows → Microsoft Edge (Chromium-based), Microsoft Visual Studio 2022 version 17.14, Microsoft Visual Studio 2026 version 18.10, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Linux, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Mac OS, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Windows, System.Formats.Cbor on .NET 10.0 installed on Linux, System.Formats.Cbor on .NET 10.0 installed on Mac OS, System.Formats.Cbor on .NET 10.0 installed on Windows, System.Formats.Cbor on .NET 8.0 installed on Linux, System.Formats.Cbor on .NET 8.0 installed on Mac OS, System.Formats.Cbor on .NET 8.0 installed on Windows, System.Formats.Cbor on .NET 9.0 installed on Linux, System.Formats.Cbor on .NET 9.0 installed on Mac OS, System.Formats.Cbor on .NET 9.0 installed on Windows
15 Oct 2026 · 21:30:54 UTCRevision noteInformation published. → Updated the Security Updates table to add KB article links for .NET 11.0. This is an informational change only; the fixed builds are unchanged.
15 Oct 2026 · 21:30:54 UTCAffected productsMessagePack 2.5.303, Microsoft Visual Studio 2022 version 17.14, Microsoft Visual Studio 2026 version 18.10, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 10.0 installed on Linux, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 10.0 installed on Mac OS, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 10.0 installed on Windows, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Linux, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Mac OS, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Windows, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 8.0 installed on Linux, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 8.0 installed on Mac OS, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 8.0 installed on Windows, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 9.0 installed on Linux, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 9.0 installed on Mac OS, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 9.0 installed on Windows → MessagePack 2.5.303, Microsoft Visual Studio 2022 version 17.14, Microsoft Visual Studio 2026 version 18.10, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Linux, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Mac OS, Microsoft.AspNetCore.SignalR.Protocols.MessagePack on .NET 11.0 installed on Windows, System.Formats.Cbor on .NET 10.0 installed on Linux, System.Formats.Cbor on .NET 10.0 installed on Mac OS, System.Formats.Cbor on .NET 10.0 installed on Windows, System.Formats.Cbor on .NET 8.0 installed on Linux, System.Formats.Cbor on .NET 8.0 installed on Mac OS, System.Formats.Cbor on .NET 8.0 installed on Windows, System.Formats.Cbor on .NET 9.0 installed on Linux, System.Formats.Cbor on .NET 9.0 installed on Mac OS, System.Formats.Cbor on .NET 9.0 installed on Windows