MajorCritical vulnerability
CVE-2021-48012 (CVSS 8.8)
NVD · officialPublished Oct 12, 2026Risk 37/100
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.
Technical details
CVSS
8.8
AV:NetworkAC:LowPR:NoneUI:None
Evidence and sources
This record is attributed to NVD. Exploitation status and remediation guidance are kept separate from the vulnerability's technical severity.
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