MajorCritical vulnerability

CVE-2026-123564 (CVSS 8.7)

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

Sveltejs devalue from 1.0.0 before 5.9.3 contains a memory exhaustion flaw in uneval, whose generated code for sparse arrays allocates memory proportional to the array's declared length when evaluated. Attackers who can influence a very large sparse array serialized by an application can exhaust memory in the browser or runtime evaluating the output.

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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