---
id: CVE-2026-62848
title: >-
  Metalama's Visual Studio inter-process named pipe allows unsafe
  deserialization that enables local code execution
summary: >-
  Metalama is a Roslyn-based open-source patterns and architecture toolkit for
  C#. From 2023.0.101-rc until 2025.1.18, 2026.0.25 and 2026.1.19, the Windows
  Visual Studio integration deserializes local named-pipe messages without
  restrictin…
severity: high
cvss: 7.3
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-502
  - CWE-913
vendor: metalama
product: Metalama
affected:
  - 'Metalama >= 2023.0.101-rc, < 2025.1.18'
  - 'Metalama >= 2025.2.0-preview, <= 2025.2.5-rc'
  - 'Metalama >= 2026.0.0-preview, < 2026.0.25'
  - 'Metalama >= 2026.1.0-preview, < 2026.1.19'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-11-06T18:06:00.227673Z'
published: '2026-10-30'
updated: '2026-11-06'
sourceUpdated: '2026-11-06T18:07:07.609Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-62848'
references:
  - url: >-
      https://github.com/metalama/Metalama/security/advisories/GHSA-h26j-4vp7-x9w2
    label: >-
      https://github.com/metalama/Metalama/security/advisories/GHSA-h26j-4vp7-x9w2
  - url: 'https://github.com/metalama/Metalama/pull/1651'
    label: 'https://github.com/metalama/Metalama/pull/1651'
  - url: >-
      https://github.com/metalama/Metalama/commit/5b4ced29f2b25631cc2e44d05b0fd5fe838b6cbe
    label: >-
      https://github.com/metalama/Metalama/commit/5b4ced29f2b25631cc2e44d05b0fd5fe838b6cbe
  - url: >-
      https://github.com/metalama/Metalama/commit/d97f52e1b53ffe4176b2b05c56ffdf1ccd2f53a9
    label: >-
      https://github.com/metalama/Metalama/commit/d97f52e1b53ffe4176b2b05c56ffdf1ccd2f53a9
  - url: 'https://github.com/metalama/Metalama/releases/tag/release/2025.1.18'
    label: 'https://github.com/metalama/Metalama/releases/tag/release/2025.1.18'
  - url: 'https://github.com/metalama/Metalama/releases/tag/release/2026.0.25'
    label: 'https://github.com/metalama/Metalama/releases/tag/release/2026.0.25'
  - url: 'https://github.com/metalama/Metalama/releases/tag/release/2026.1.19'
    label: 'https://github.com/metalama/Metalama/releases/tag/release/2026.1.19'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-62848'
  - url: 'https://github.com/advisories/GHSA-h26j-4vp7-x9w2'
tags:
  - cve.org
  - ghsa
  - nuget
epss: 0.00186
epssPercentile: 0.083
aliases:
  - GHSA-h26j-4vp7-x9w2
ecosystem: nuget
patched:
  - Metalama.Framework 2026.1.19
  - Metalama.Framework 2025.1.18
  - Metalama.Framework 2026.0.25
ingestedAt: '2026-11-03T16:49:26.418Z'
---

## Overview

Metalama is a Roslyn-based open-source patterns and architecture toolkit for C#. From 2023.0.101-rc until 2025.1.18, 2026.0.25 and 2026.1.19, the Windows Visual Studio integration deserializes local named-pipe messages without restricting which CLR types can be instantiated. The pipe connects `devenv`, the out-of-process Roslyn code-analysis process and the `CodeLens` process, and has the predictable name `Metalama_{role}_{processId}_{hash(PackageVersion)}`. Releases from the first public 2023.0 line through 2026.0.x use Newtonsoft.Json with `TypeNameHandling.All`; the later `SerializationBinder` only remaps assembly names, and `BindToType` resolves arbitrary wire-supplied types without an allow-list. Releases 2026.1.0 through 2026.1.18 use typeless MessagePack with `TypelessObjectResolver` and likewise instantiate arbitrary types. A same-user local process able to write to the pipe can send crafted messages that lead to arbitrary code execution with confidentiality, integrity and availability impacts inside the affected Visual Studio process. Default Windows pipe ACLs limit writers to the same logged-in user, so this does not escalate privileges or cross a security boundary; command-line and MSBuild-only builds do not use the channel. The maintained Metalama + PostSharp extension is affected from 2024.1 through 2026.1.4, while earlier Metalama-free PostSharp versions are unaffected. The retired Metalama and Caravela extensions remain affected and require removal or migration. The framework issue is fixed in versions 2025.1.18, 2026.0.25 and 2026.1.19; the maintained Metalama + PostSharp Visual Studio extension is fixed in version 2026.1.5. The retired Metalama and Caravela extensions require removal or migration.

## Affected

- `Metalama >= 2023.0.101-rc, < 2025.1.18`
- `Metalama >= 2025.2.0-preview, <= 2025.2.5-rc`
- `Metalama >= 2026.0.0-preview, < 2026.0.25`
- `Metalama >= 2026.1.0-preview, < 2026.1.19`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-62848)

Affected packages:

- `Metalama.Framework >= 2026.1.0-preview, < 2026.1.19`
- `Metalama.Framework < 2025.1.18`
- `Metalama.Framework >= 2026.0.1-preview, < 2026.0.25`

Patched in:

- `Metalama.Framework 2026.1.19`
- `Metalama.Framework 2025.1.18`
- `Metalama.Framework 2026.0.25`

Source: https://github.com/advisories/GHSA-h26j-4vp7-x9w2