CVE-2026-81176

Svelte devalue: DoS via malformed input

Published Sep 16, 2026 CVSS 3.1 · 5.3 Medium EPSS < 1% KEV · Not listed
Description
Svelte devalue is a JavaScript library that serializes values into strings when JSON.stringify isn't sufficient for the job. Prior to 5.9.2, devalue.parse does not reject out-of-bounds indices that are greater than or equal to values.length in src/parse.js. A specially crafted untrusted payload can make the parser alternate between array representations, producing quadratic work as the payload grows and causing denial of service in applications that parse untrusted devalue data. This issue is fixed in version 5.9.2.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-9rgm-9g3h-6x36 Svelte devalue: DoS via malformed input
History
Type Values Removed Values Added
First Time appeared Svelte
Svelte devalue
Vendors & Products Svelte
Svelte devalue
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Svelte devalue is a JavaScript library that serializes values into strings when JSON.stringify isn't sufficient for the job. Prior to 5.9.2, devalue.parse does not reject out-of-bounds indices that are greater than or equal to values.length in src/parse.js. A specially crafted untrusted payload can make the parser alternate between array representations, producing quadratic work as the payload grows and causing denial of service in applications that parse untrusted devalue data. This issue is fixed in version 5.9.2.
Title Svelte devalue: DoS via malformed input
Weaknesses CWE-770
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 17, 2026, 7:25 PM
Reserved
Aug 26, 2026, 4:26 PM
Status
Deferred
Published
Sep 16, 2026, 7:17 PM
Modified
Sep 30, 2026, 5:51 PM
Severity
Moderate
Public date
Sep 16, 2026, 6:34 PM