{"id":"CVE-2026-62847","revision":"bd64f37d2119427db983ff702be6e8c8","records":[{"revision":"bd64f37d2119427db983ff702be6e8c8","observedAt":"2026-10-30T23:45:26.581+00:00","statement":{"source":"cve-program","id":"CVE-2026-62847","aliases":[],"title":"Metalama: Local code execution via DLL planting in world-writable temporary directories (Linux/macOS)","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.","state":0,"publishedAt":"2026-10-30T20:23:50.882+00:00","modifiedAt":"2026-10-30T22:13:12.107+00:00","affected":[{"ecosystem":"Vendor product","name":"Metalama","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"metalama\",\n                    \"product\": \"Metalama\",\n                    \"versions\": [\n                        {\n                            \"version\": \"< 2025.1.18\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \">= 2025.2.0-preview, <= 2025.2.5-rc\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \">= 2026.0.0-preview, < 2026.0.25\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \">= 2026.1.0-preview, < 2026.1.19\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H","score":8.2,"severity":"HIGH"}],"references":["https://github.com/metalama/Metalama/security/advisories/GHSA-m6wq-39m7-9xpp","https://github.com/metalama/Metalama/pull/1650","https://github.com/metalama/Metalama/commit/09911349a916e82194b1cfaa6d0a38acad928fc9","https://github.com/metalama/Metalama/commit/92c4feecfce86d18fcb007ab6d3a1b4383326a2e","https://github.com/metalama/Metalama/releases/tag/release/2025.1.18","https://github.com/metalama/Metalama/releases/tag/release/2026.0.25","https://github.com/metalama/Metalama/releases/tag/release/2026.1.19"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-62847","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-62847","identifiers":["CVE-2026-62847"]},"retained":false,"historicalAffected":[]}],"coverage":[]}