{"id":"CVE-2026-47261","revision":"c5b37f25ad754a95b33bae9449ca71d7","records":[{"revision":"c5b37f25ad754a95b33bae9449ca71d7","observedAt":"2026-10-25T12:17:26.301+00:00","statement":{"source":"nvd","id":"CVE-2026-47261","aliases":[],"title":"Wasmtime is a runtime for WebAssembly. In versions prior to 24.0.9, 36.0.10, and 44.0.2, when a filesystem preopen is given DirPerms::all() and FilePerms::READ without FilePerms::WRITE, this access control mechanism can be bypassed via the …","description":"Wasmtime is a runtime for WebAssembly. In versions prior to 24.0.9, 36.0.10, and 44.0.2, when a filesystem preopen is given DirPerms::all() and FilePerms::READ without FilePerms::WRITE, this access control mechanism can be bypassed via the wasip2 descriptor.open-at or wasip1 path_open interfaces by opening a file with only the OpenFlags::TRUNCATE oflag. The root cause is that the clause handling OpenFlags::TRUNCATE in crates/wasi/src/filesystem.rs (Dir::open_at, lines 967–969) did not set open_mode |= OpenMode::WRITE;, which is later used for the access control check against FilePerms to determine whether opening the file is permitted; the single-line fix adds that missing assignment, after which the affected calls correctly fail with error-code.not-permitted and ERRNO_PERM respectively. Only wasmtime-wasi embeddings that combine DirPerms::MUTATE with FilePerms::READ are affected by this bug. In particular, the Wasmtime project's wasmtime-cli's use of wasmtime-wasi is not affected, because it always sets FilePerms::all() for all preopens. This issue has been fixed in versions 24.0.9, 36.0.10 and44.0.2.","state":0,"publishedAt":"2026-06-15T21:17:11.153+00:00","modifiedAt":"2026-06-17T16:42:08.35+00:00","affected":[],"metrics":[{"system":"CVSS 3.1 · security-advisories@github.com · Secondary","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","score":7.5,"severity":"HIGH"}],"references":["https://github.com/bytecodealliance/wasmtime/releases/tag/v24.0.9","https://github.com/bytecodealliance/wasmtime/releases/tag/v36.0.10","https://github.com/bytecodealliance/wasmtime/releases/tag/v44.0.2","https://github.com/bytecodealliance/wasmtime/releases/tag/v45.0.0","https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-2r75-cxrj-cmph"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-47261","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Analyzed","weaknesses":["CWE-284","NVD-CWE-noinfo"],"productCriteria":["cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:*"],"sourceDates":{"published":"2026-06-15T21:17:11.153","lastModified":"2026-06-17T16:42:08.350"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2026-47261","identifiers":["CVE-2026-47261"]},"retained":false,"historicalAffected":[]}],"coverage":[]}