Metalama: Local code execution via DLL planting in world-writable temporary directories (Linux/macOS)
Impact
Metalama versions before 2025.1.18, 2026.0.25, and 2026.1.19 have a local code execution vulnerability via DLL planting in world-writable temporary directories on Linux and macOS. A local unprivileged user can plant a malicious DLL, which may be executed by a higher-privileged developer or build account. This permits privilege escalation and other security issues.
Summarized by @cf/meta/llama-3.3-70b-instruct-fp8-fast. Verify details against the original sources.Affected packages
Affected products
Vendor version evidence. Product records are separate from automatic dependency matching.
metalama · GitHub_M
Metalama
4 ranges
metalama · GitHub_M
Metalama
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affected
< 2025.1.18
>= 2025.2.0-preview, <= 2025.2.5-rc
>= 2026.0.0-preview, < 2026.0.25
>= 2026.1.0-preview, < 2026.1.19
Other versions: unknown
Original source description
Metalama is a Roslyn-based open-source patterns and architecture toolkit for C#. Prior to 2025.1.18, 2026.0.25 and 2026.1.19, Metalama.Framework and Metalama.Tool load and execute compile-time assemblies, auxiliary executable tools and embedded helper assemblies from predictable temporary directories. On Linux and macOS, the default Path.GetTempPath() location is world-writable, and existing artifacts are trusted based on sentinel or .completed marker files rather than integrity verification. A local unprivileged user on a shared machine or CI/build agent can pre-create the deterministic directory structure and plant a malicious DLL with the matching sentinel. When a higher-privileged developer or build account subsequently builds, Metalama skips regeneration and executes the planted artifact in the compiler, IDE or MSBuild process as the building user. This permits cross-user privilege escalation, reading source and secrets, supply-chain tampering with build output, or disrupting builds. Default Windows per-user temporary directories are protected by ACLs and are not affected. Deployer-selected insecure cache locations are outside the vulnerability's scope. This issue is fixed in versions 2025.1.18, 2026.0.25 and 2026.1.19.
Inside the record
Evidence available
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Original records
CVE-2026-62847View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.
cve.new JSON →Underlying weaknesses
The source’s classification of what caused the vulnerability.
Contributing organizations · 2
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Additional data publisher
What changed
Follow changes- CVE · CVE-2026-62847
Observed 2026-10-30T22:48:26.578Z · upstream updated 2026-10-30T22:13:12.107Z
Prioritization updated
before
[]
after
[ { "source": "CISA-ADP", "type": "SSVC", "role": "CISA Coordinator", "timestamp": "2026-10-30T21:21:14.933972Z", "decisions": [ { "name": "Exploitation", "value": "none" }, { "name": "Automatable", "value": "no" }, { "name": "Technical Impact", "value": "total" } ] } ]
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