MajorCritical vulnerability

CVE-2026-123566 (CVSS 8.7)

NVD · officialPublished Nov 8, 2026Risk 37/100EPSS 0.3%

Sveltejs devalue before 5.9.3 contains a denial of service vulnerability that allows attackers to cause CPU amplification by supplying sparse arrays to uneval. Attackers who influence sparse values passed to uneval can force synchronous work proportional to the declared array length, blocking the event loop.

Technical details

CVSS

8.7

AV:NetworkAC:LowPR:NoneUI:None

Evidence and sources

This record is attributed to NVD. Exploitation status and remediation guidance are kept separate from the vulnerability's technical severity.

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