CVE-2026-123565

CVSS 8.7 (high) · published 2026-11-08

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.

Weakness: CWE-400

Source: NVD CVE-2026-123565

References

• https://github.com/sveltejs/devalue/security/advisories/GHSA-mcm9-63f2-9j32
• https://www.vulncheck.com/advisories/devalue-before-5.9.3-quadratic-expansion-denial-of-service-via-uneval

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