Sveltejs devalue before 5.9.3 contains a resource exhaustion vulnerability where repeated primitive strings cause quadratic expansion in the uneval function. Attackers can supply a small crafted payload that is parsed and then passed to uneval, producing a very large serialized string that exhausts memory or CPU.
History

Sun, 08 Nov 2026 01:45:00 +0000

Type Values Removed Values Added
Description Sveltejs devalue before 5.9.3 contains a resource exhaustion vulnerability where repeated primitive strings cause quadratic expansion in the uneval function. Attackers can supply a small crafted payload that is parsed and then passed to uneval, producing a very large serialized string that exhausts memory or CPU.
Title Devalue before 5.9.3 Quadratic Expansion Denial of Service via uneval
First Time appeared Svelte
Svelte devalue
Weaknesses CWE-400
CPEs cpe:2.3:a:svelte:devalue:*:*:*:*:*:*:*:*
Vendors & Products Svelte
Svelte devalue
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published: 2026-11-08T01:38:04.469Z

Updated: 2026-11-10T17:58:28.362Z

Reserved: 2026-11-06T00:53:14.312Z

Link: CVE-2026-123565

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-11-08T02:16:49.040

Modified: 2026-11-10T18:17:25.820

Link: CVE-2026-123565

cve-icon Redhat

No data.