Vulnerability GHSA-mwv9-gp5h-frr4
Low Risk
LOW RISK
CVSS Score: 3.0
Score Range: < 4.0
Low severity vulnerabilities (CVSS < 4.0). Hygiene issues that can accumulate but pose lower immediate risk.
8 months ago
March 12, 2026 at 04:38 PM UTC
Sveltejs devalue's `devalue.parse` and `devalue.unflatten` emit objects with `__proto__` own properties
>=4.0.0 <5.6.4
>=4.0.0 <5.6.4
Summary
Sveltejs devalue's `devalue.parse` and `devalue.unflatten` emit objects with `__proto__` own properties
Details
In some circumstances, devalue.parse and devalue.unflatten could emit objects with __proto__ own properties. This in and of itself is not a security vulnerability (and is possible with, for example, JSON.parse as well), but it can result in prototype injection if downstream code handles it incorrectly:
const result = devalue.parse(/* input creating an object with a __proto__ property */);
const target = {};
Object.assign(target, result); // target's prototype is now polluted
Related Vulnerabilities
Other vulnerabilities affecting the same packages
High Risk
1 month ago
devalue: `stringify`/`uneval` serialize shared memory
>=5.1.0 <5.9.3 GHSA-j22f-vq7h-c4qm
>=5.1.0 <5.9.3 GHSA-j22f-vq7h-c4qm
Medium Risk
1 month ago
devalue: Residual sparse-array CPU amplification in uneval
<5.9.3 GHSA-hx4r-w6wj-j8fg
<5.9.3 GHSA-hx4r-w6wj-j8fg
High Risk
1 month ago
devalue: Repeated primitive strings cause quadratic expansion in uneval
<5.9.3 GHSA-mcm9-63f2-9j32
<5.9.3 GHSA-mcm9-63f2-9j32
Low Risk
1 month ago
devalue: Sparse arrays emitted by uneval cause eager allocation when evaluated
>=1.0.0 <5.9.3 GHSA-wf3x-273g-mvxv
>=1.0.0 <5.9.3 GHSA-wf3x-273g-mvxv
High Risk
1 month ago
devalue: Custom ArrayBuffer revivers can bypass typed-array allocation validation
<5.9.3 GHSA-r9w8-h9r3-54w4
<5.9.3 GHSA-r9w8-h9r3-54w4
Impacted packages
Timeline
Published
8 months ago
March 12, 2026 at 04:38 PM UTC
Fixed (5.6.4)
7 months ago
March 16, 2026 at 12:38 AM UTC
Last Modified
12 hours ago
November 08, 2026 at 10:56 AM UTC