CVE-2026-62848

Name of the Vulnerable Software and Affected Versions Metalama versions 2023.0.101-rc through 2025.1.17 Metalama versions 2026.0.x through 2026.0.24 Metalama versions 2026.1.0 through 2026.1.18 Metalama + PostSharp extension versions 2024.1 through 2026.1.4 Metalama extension (affected versions not specified) Caravela extension (affected versions not specified)

Description The Windows Visual Studio integration deserializes local named-pipe messages without restricting which Common Language Runtime (CLR) types can be instantiated. The affected pipe connects devenv, the out-of-process Roslyn code-analysis process, and the CodeLens process, using a predictable name format Metalama {role} {processId} {hash(PackageVersion)}. In versions up to 2026.0.x, the system uses Newtonsoft.Json with TypeNameHandling.All, where the BindToType function resolves arbitrary types without an allow-list. Versions 2026.1.0 through 2026.1.18 use typeless MessagePack with TypelessObjectResolver, which also allows the instantiation of arbitrary types. A local process running under the same user account can send crafted messages to the pipe to achieve arbitrary code execution within the affected Visual Studio process. Command-line and MSBuild-only builds are not affected.

Recommendations Update Metalama to versions 2025.1.18, 2026.0.25, or 2026.1.19. Update Metalama + PostSharp extension to version 2026.1.5. Remove or migrate the retired Metalama extension. Remove or migrate the retired Caravela extension.