{"cve":"CVE-2026-63376","nvd":{"published":"2026-09-03T21:17:21.513","modified":"2026-09-09T21:09:13.080","status":"Deferred","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L","score":8.2},"cwes":["CWE-1321"],"references":["https://github.com/BinaryMuse/toml-node/commit/def6ab5ea99038c0dd482cd6af1745a6af8b4c44","https://github.com/BinaryMuse/toml-node/commit/dfaff662276adc38a2e03df3139f7119b0185463","https://github.com/BinaryMuse/toml-node/security/advisories/GHSA-v5mp-jgw5-2x6j","https://github.com/BinaryMuse/toml-node/security/advisories/GHSA-v5mp-jgw5-2x6j"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:52:03.409947763+00:00"},"epss":{"cve":"CVE-2026-63376","score":0.00683,"percentile":0.52554,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-v5mp-jgw5-2x6j","url":"https://osv.dev/vulnerability/GHSA-v5mp-jgw5-2x6j","summary":"toml-node: Prototype Pollution Leads to `Object.prototype` Corruption via `__proto__` Key-Path Desynchronization","modified":"2026-09-03T21:10:38.140499Z","packages":[{"ecosystem":"npm","name":"toml","purl":"pkg:npm/toml","ranges":["<4.1.2"],"fixed":["4.1.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}