CVE-2026-62848
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AI Threat Summary
CVE-2026-62848 is a high-severity vulnerability with a CVSS score of 7.3 affecting the target software. Threat hunters should monitor for exploit attempts and apply vendor patches immediately.
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.
Attack Chain
Attacker identifies vulnerable service instances using Shodan, Censys, or active scanning
Attacker crafts malicious payload exploiting CVE-2026-62848 to achieve remote code execution
Attacker executes arbitrary OS commands or shellcode in the context of the vulnerable process
Attacker installs backdoor, cron job, or web shell for persistent access
Attacker uses compromised host as pivot point to access internal network resources
MITRE ATT&CK Techniques
Attacker exploits the vulnerability in an internet-facing service to gain initial access
Post-exploitation shell commands executed through the vulnerability
Attacker downloads malware or tools after gaining code execution
Indicators of Compromise
| Type | Value | Description | |
|---|---|---|---|
| user_agent | Mozilla/5.0 (compatible; exploit/1.0) |
Generic exploit scanner user agent pattern | |
| url | /api/vuln-endpoint?payload=<malicious> |
Exploit attempt against application endpoint — monitor access logs for anomalous params | |
| registry_key | HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\backdoor |
Persistence mechanism after successful RCE |
Remediation
Quick Facts
| CVE ID | CVE-2026-62848 |
| CVSS Score | 7.3 |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H |
| Published | 2026-10-30 |
| Exploited | No |
| CISA KEV | No |
| PoC | Available |
References
- https://github.com/metalama/Metalama/commit/5b4ced29f2b25631…
- https://github.com/metalama/Metalama/commit/d97f52e1b53ffe41…
- https://github.com/metalama/Metalama/pull/1651
- https://github.com/metalama/Metalama/releases/tag/release/20…
- https://github.com/metalama/Metalama/releases/tag/release/20…
- https://github.com/metalama/Metalama/releases/tag/release/20…
- https://github.com/metalama/Metalama/security/advisories/GHS…