Prototype Pollution CVE-2025-57820
HIGHCVSS VectorNVD
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H/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
Lifecycle Timeline
3Blast Radius
ecosystem impact- 2 npm packages depend on devalue (1 direct, 1 indirect)
Ecosystem-wide dependent count for version 5.3.2.
DescriptionNVD
Svelte devalue is a utility library. Prior to version 5.3.2, a string passed to devalue.parse could represent an object with a __proto__ property and devalue.parse does not check that an index is numeric. This could result in assigning prototypes to objects and properties, leading to prototype pollution. This issue has been fixed in version 5.3.2
AnalysisAI
Svelte devalue is a utility library. Rated high severity (CVSS 7.9), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Technical ContextAI
This vulnerability is classified as Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution) (CWE-1321), which allows attackers to modify object prototypes to inject properties affecting application logic. Svelte devalue is a utility library. Prior to version 5.3.2, a string passed to devalue.parse could represent an object with a __proto__ property and devalue.parse does not check that an index is numeric. This could result in assigning prototypes to objects and properties, leading to prototype pollution. This issue has been fixed in version 5.3.2 Version information: version 5.3.2.
Affected ProductsAI
See vendor advisory for affected versions.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Freeze prototypes, validate object keys, avoid recursive merging of untrusted data.
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External POC / Exploit Code
Leaving vuln.today