{"id":"CVE-2026-63376","summary":"toml-node: Prototype Pollution Leads to `Object.prototype` Corruption via `__proto__` Key-Path Desynchronization","details":"toml-node is a TOML parser for Node.js and the browser. Prior to 4.1.2, toml.parse() in lib/compiler.js can be tricked by a table path such as a.b.y.__proto__.__proto__, allowing traversal from a scalar value into Number.prototype and Object.prototype. The currentPath tracking value uses both arrays and strings, so valueAssignments records a comma-joined path such as a,b.y while deepRef checks the dot-joined path a.b.y, allowing the duplicate-key guard to miss and attacker-controlled keys to be written to Object.prototype. A table-array prefix-clearing path in addTableArray can also erase guard state before the same __proto__ traversal. Injected properties become visible throughout the Node.js process and can cause denial of service, logic or authorization bypass, or code execution when an application contains a suitable gadget. This issue is fixed in version 4.1.2.","aliases":["GHSA-v5mp-jgw5-2x6j"],"modified":"2026-09-06T03:30:38.328782529Z","published":"2026-09-03T20:34:57.129Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63376.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-1321"]},"references":[{"type":"ADVISORY","url":"https://github.com/BinaryMuse/toml-node/security/advisories/GHSA-v5mp-jgw5-2x6j"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63376.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63376"},{"type":"FIX","url":"https://github.com/BinaryMuse/toml-node/commit/def6ab5ea99038c0dd482cd6af1745a6af8b4c44"},{"type":"FIX","url":"https://github.com/BinaryMuse/toml-node/commit/dfaff662276adc38a2e03df3139f7119b0185463"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/binarymuse/toml-node","events":[{"introduced":"0"},{"fixed":"def6ab5ea99038c0dd482cd6af1745a6af8b4c44"},{"fixed":"dfaff662276adc38a2e03df3139f7119b0185463"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"4.1.2"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["v4.1.1","v4.1.0","v4.0.1","v4.0.0","v3.0.0","v2.3.6","v2.3.5","v2.3.4","v2.3.3","v2.3.1","2.3.0","2.2.3","2.2.2","2.2.1","2.2.0","2.1.1","2.1.0","2.0.6","2.0.5","2.0.4","2.0.3","2.0.2","2.0.1","2.0.0","1.0.4","1.0.3","1.0.2","1.0.1","1.0.0","0.4.1","0.4.0","0.3.0","0.2.0","0.1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-63376.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L"}]}