Description
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.
Scores
CVSS v3
7.5
EPSS
0.0014
EPSS Percentile
33.2%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-1321
Status
published
Products (2)
npm/devalue
0 - 5.6.4npm
svelte/devalue
< 5.6.4
Published
Mar 11, 2026
Tracked Since
Mar 12, 2026