Vulnerability · CVE-2026-62847
Metalama allows local code execution through DLL planting in shared temporary directories
Published Oct 14, 2026 · catalog updated Oct 14, 2026 · Metalama allows local code
Open the advisory
Exploitation likelihood is not on this record for CVE-2026-62847. A missing EPSS score is not a low risk. Compare Metalama allows local code with the linked advisory before you change production.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (Metalama allows local code).
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- EPSS is missing. A missing score is not a low risk.
- Severity
- High8.2
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- Not in the current FIRST EPSS dataset
- Remediation
- Version ranges on file
- Affected products
- NuGet Metalama.Framework · NuGet Metalama.Tool · nuget Metalama.Framework · nuget Metalama.Tool · nuget metalama.framework · nuget metalama.tool
## Summary Metalama loaded and executed compile-time assemblies, auxiliary executable tools, and embedded helper assemblies from predictable temporary directories. On Linux and macOS the default cache location was the world-writable system temporary directory ( , i.e. ), and previously-generated artifacts were trusted based on the presence of a sentinel/ marker file rather than on any integrity verification. A local, unprivileged user on a shared machine or CI/build agent can pre-create the deterministic cache directory structure and plant a malicious DLL together with the matching sentinel file. When a higher-privileged user (or build/service account) subsequently runs a build, Metalama finds the sentinel, skips regeneration, and loads and executes the attacker-supplied assembly inside the compiler / IDE / MSBuild process. Affected load-and-execute paths: - the cache of compile-time assemblies that Metalama generates from your aspects; - auxiliary executable tools that Metalama extracts to a local directory and then launches; - embedded .NET helper assemblies that Metalama extracts to a local directory and loads into the build / IDE process. ## Impact Arbitrary code execution in the security context of the building user — i.e. a local privilege escalation across user accounts on shared POSIX systems (multi-user developer machines, CI/build agents). The attacker obtains code execution as the victim without holding the victim's privileges, and can read source/secrets, tamper with build output (supply-chain injection), or disrupt builds. ## Affected configurations - **Linux and macOS, default configuration — affected.** The shipped default uses the world-writable system temp directory. - **Windows, default configuration — not affected.** The default per-user temporary directory is protected by OS ACLs, so cross-user planting is not possible. - The environment variable is a deployer-controlled override and is **out of scope**: pointing it at an insecure (e.g. world-wri
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- NuGet Metalama.Framework0 → 2025.1.18
- NuGet Metalama.Framework2026.0.0-preview → 2026.0.25
- NuGet Metalama.Framework2026.1.0-preview → 2026.1.19
- NuGet Metalama.Tool0 → 2025.1.18
- NuGet Metalama.Tool2026.0.0-preview → 2026.0.25
- NuGet Metalama.Tool2026.1.0-preview → 2026.1.19
- nuget Metalama.Framework< 2025.1.18
- nuget Metalama.Framework>= 2026.0.0-preview, < 2026.0.25
- nuget Metalama.Framework>= 2026.1.0-preview, < 2026.1.19
- nuget Metalama.Tool< 2025.1.18
- nuget Metalama.Tool>= 2026.0.0-preview, < 2026.0.25
- nuget Metalama.Tool>= 2026.1.0-preview, < 2026.1.19
- nuget metalama.frameworkversion unspecified
- nuget metalama.toolversion unspecified
How to fix CVE-2026-62847
Recommended remediation
Affected version ranges suggest a fixed boundary. Verify against the vendor advisory for your release.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
Exploitation likelihood is not on this record for CVE-2026-62847. A missing EPSS score is not a low risk. Compare Metalama allows local code with the linked advisory before you change production.
Which versions are affected?
Compare what you have installed with Metalama.Framework 0 → 2025.1.18; Metalama.Framework 2026.0.0-preview → 2026.0.25; Metalama.Framework 2026.1.0-preview → 2026.1.19; Metalama.Tool 0 → 2025.1.18. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-377; CWE-427: Uncontrolled Search Path Element. EPSS is absent from the current FIRST dataset. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Oct 14, 2026 · GitHub Advisory Database
Detected
## Summary Metalama loaded and executed compile-time assemblies, auxiliary executable tools, and embedded helper assemblies from predictable temporary directories. On Linux and macOS the default cache location was the world-writable system temporary directory ( , i.e. ), and previously-generated artifacts were trusted based on the presence of a sentinel/ marker file rather than on any integrity ve
Oct 14, 2026 · GitHub Advisory Database
Fix available
Metalama.Framework fixed in 2026.1.19; Metalama.Tool fixed in 2026.1.19; Metalama.Framework fixed in 2025.1.18; Metalama.Tool fixed in 2025.1.18
Oct 14, 2026 · GitHub Advisory Database
Fix available
Metalama.Framework fixed in 2026.1.19
Oct 14, 2026 · GitHub Advisory Database
Fix available
Metalama.Tool fixed in 2026.1.19
Oct 14, 2026 · GitHub Advisory Database
Fix available
Metalama.Framework fixed in 2025.1.18
Oct 14, 2026 · GitHub Advisory Database
Fix available
Metalama.Tool fixed in 2025.1.18
Oct 14, 2026 · GitHub Advisory Database
Fix available
Metalama.Tool fixed in 2026.0.25
Oct 14, 2026 · GitHub Advisory Database
Fix available
Metalama.Framework fixed in 2026.0.25
Oct 14, 2026 · GitHub Advisory Database
Updated
## Summary Metalama loaded and executed compile-time assemblies, auxiliary executable tools, and embedded helper assemblies from predictable temporary directories. On Linux and macOS the default cache location was the world-writable system temporary directory ( , i.e. ), and previously-generated artifacts were trusted based on the presence of a sentinel/ marker file rather than on any integrity ve
Sources
- CVE.orgVulnerability recordCVE-2026-62847
Official CVE identifier
cve.org - GitHub Advisory DatabasePackage advisoryGHSA-m6wq-39m7-9xpp
GitHub Advisory Database record mirrored by OSV.
github.com - GitLab Advisory DatabasePackage advisoryCVE-2026-62847
Metalama loaded and executed compile-time assemblies, auxiliary executable tools, and embedded helper assemblies from predictable temporary directories. On Linux and macOS the default cache location was the world-writable system temporary directory (Path.GetTempPath(), i.e. /tmp), and previously-generated artifacts were trusted based on the presence of a sentinel/.completed marker file rather than
advisories.gitlab.com - OpenSSF OSV / OSV ScannerPackage advisoryGHSA-m6wq-39m7-9xpp
Metalama allows local code execution through DLL planting in shared temporary directories
osv.dev
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.