{"id":"CVE-2021-48012","aliases":["EUVD-2021-34885","GHSA-qqfj-vf92-g76j"],"status":"published","title":"fast-toml through 0.5.4 Prototype Pollution via __proto__ Keys in Parsed TOML","description":"fast-toml through 0.5.4 contains a prototype pollution vulnerability that allows attackers to modify Object.prototype by supplying TOML containing __proto__, constructor or prototype key segments. Attackers can pass [__proto__] or [constructor.prototype] table headers or __proto__.x dotted keys to parse() to pollute all objects, causing denial of service or authorization bypass.","severity":{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00414,"percentile":0.36046,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-1321"],"published":"2026-10-12T20:55:05Z","modified":"2026-10-26T18:17:04Z","products":[{"vendor":"gin-quin","product":"fast-toml"}],"references":[{"url":"https://github.com/Gin-Quin/fast-toml/issues/8","tags":["issue-tracking"]},{"url":"https://github.com/Gin-Quin/fast-toml/pull/3","tags":["issue-tracking","patch"]},{"url":"https://github.com/Gin-Quin/fast-toml","tags":["product"]},{"url":"https://www.vulncheck.com/advisories/fast-toml-through-0.5.4-prototype-pollution-via-proto-keys-in-parsed-toml","tags":["third-party-advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-48012"},{"url":"https://github.com/advisories/GHSA-qqfj-vf92-g76j"}],"sources":{"cve":[{"id":"CVE-2021-48012","title":"fast-toml through 0.5.4 Prototype Pollution via __proto__ Keys in Parsed TOML","description":"fast-toml through 0.5.4 contains a prototype pollution vulnerability that allows attackers to modify Object.prototype by supplying TOML containing __proto__, constructor or prototype key segments. Attackers can pass [__proto__] or [constructor.prototype] table headers or __proto__.x dotted keys to parse() to pollute all objects, causing denial of service or authorization bypass.","status":"published","published":"2026-10-12T20:55:05.966Z","modified":"2026-10-26T17:37:12.265Z","cvss":[{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high","assessor":"cna"},{"version":"3.1","score":8.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L","level":"high","assessor":"cna"}],"cwes":["CWE-1321"],"updated_at":"2026-11-02T14:33:04.360272Z"}],"euvd":[{"id":"EUVD-2021-34885","description":"fast-toml through 0.5.4 contains a prototype pollution vulnerability that allows attackers to modify Object.prototype by supplying TOML containing __proto__, constructor or prototype key segments. Attackers can pass [__proto__] or [constructor.prototype] table headers or __proto__.x dotted keys to parse() to pollute all objects, causing denial of service or authorization bypass.","status":"published","published":"2026-10-12T20:55:05Z","modified":"2026-10-26T17:37:12Z","cvss":[{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T16:59:28.784227Z"}],"ghsa":[{"id":"GHSA-qqfj-vf92-g76j","title":"fast-toml through 0.5.4 contains a prototype pollution vulnerability that allows attackers to...","description":"fast-toml through 0.5.4 contains a prototype pollution vulnerability that allows attackers to modify Object.prototype by supplying TOML containing __proto__, constructor or prototype key segments. Attackers can pass [__proto__] or [constructor.prototype] table headers or __proto__.x dotted keys to parse() to pollute all objects, causing denial of service or authorization bypass.","status":"published","published":"2026-10-12T21:31:57Z","modified":"2026-10-12T21:31:58Z","cvss":[{"version":"3.1","score":8.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L","level":"high"},{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"}],"cwes":["CWE-1321"],"updated_at":"2026-11-02T15:13:07.940274Z"}],"nvd":[{"id":"CVE-2021-48012","description":"fast-toml through 0.5.4 contains a prototype pollution vulnerability that allows attackers to modify Object.prototype by supplying TOML containing __proto__, constructor or prototype key segments. Attackers can pass [__proto__] or [constructor.prototype] table headers or __proto__.x dotted keys to parse() to pollute all objects, causing denial of service or authorization bypass.","status":"published","published":"2026-10-12T21:17:06.057Z","modified":"2026-10-26T18:17:04.217Z","cvss":[{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"},{"version":"3.1","score":8.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L","level":"high","assessor":"secondary"}],"cwes":["CWE-1321"],"updated_at":"2026-11-02T14:07:09.005706Z"}]}}