CVE-2026-30226 MEDIUM

CVE-2026-30226: devalue has prototype pollution in devalue.parse and devalue.unflatten

Vendor Sveltejs
Product devalue
Weakness CWE-1321
Published March 11, 2026
Last update March 12, 2026
View on NVD All CVEs

CVSS base score

6.3/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality —
Integrity —

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

What the vulnerability does

01Description

Svelte devalue is a JavaScript library that serializes values into strings when JSON.stringify isn't sufficient for the job. In devalue v5.6.3 and earlier, devalue.parse and devalue.unflatten were susceptible to prototype pollution via maliciously crafted payloads. Successful exploitation could lead to Denial of Service (DoS) or type confusion. This vulnerability is fixed in 5.6.4.

Key dates

02Disclosure timeline

March 11, 2026 CVE published
March 12, 2026 Record updated