CVE-2026-62848
Metalama's Visual Studio inter-process named pipe allows unsafe deserialization that enables local code execution
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High7.3 | CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H |
| NVDNVD · Deferred | 3.1 | High7.3 | CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.19% · top 92% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.3.
Weakness
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- NuGetMetalama.FrameworkGHSA-h26j-4vp7-x9w2 (opens in a new tab)
References (7)
- https://github.com/metalama/Metalama/security/advisories/GHSA-h26j-4vp7-x9w2 (opens in a new tab)x_refsource_CONFIRM
- https://github.com/metalama/Metalama/pull/1651 (opens in a new tab)x_refsource_MISC
- https://github.com/metalama/Metalama/commit/5b4ced29f2b25631cc2e44d05b0fd5fe838b6cbe (opens in a new tab)x_refsource_MISC
- https://github.com/metalama/Metalama/commit/d97f52e1b53ffe4176b2b05c56ffdf1ccd2f53a9 (opens in a new tab)x_refsource_MISC
- https://github.com/metalama/Metalama/releases/tag/release/2025.1.18 (opens in a new tab)x_refsource_MISC
- https://github.com/metalama/Metalama/releases/tag/release/2026.0.25 (opens in a new tab)x_refsource_MISC
- https://github.com/metalama/Metalama/releases/tag/release/2026.1.19 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-h26j-4vp7-x9w2 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-62848)Record last updated .