{"id":"CVE-2026-123566","title":"Devalue before 5.9.3 CPU Amplification Denial of Service via uneval","summary":"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 …","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"cna","cwe":["CWE-400"],"vendor":"sveltejs","product":"devalue","affected":["devalue < 5.9.3"],"published":"2026-11-08","updated":"2026-11-08","sourceUpdated":"2026-11-08T01:38:05.159Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-123566","references":[{"url":"https://github.com/sveltejs/devalue/security/advisories/GHSA-hx4r-w6wj-j8fg","label":"GitHub Security Advisory (GHSA-hx4r-w6wj-j8fg)"},{"url":"https://www.vulncheck.com/advisories/devalue-before-5.9.3-cpu-amplification-denial-of-service-via-uneval","label":"VulnCheck Advisory: Devalue before 5.9.3 CPU Amplification Denial of Service via uneval"}],"tags":["cve.org"],"ingestedAt":"2026-11-08T02:43:18.660Z","slug":"CVE-2026-123566","body":"## Overview\n\nSveltejs 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.\n\n## Affected\n\n- `devalue < 5.9.3`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}