{"affected":[{"defaultStatus":"unaffected","ecosystem":"npm","packageName":"devalue","product":"devalue","source":"CNA: VulnCheck","vendor":"sveltejs","versions":[{"lessThan":"5.9.3","status":"affected","version":"0","versionType":"semver"},{"status":"unaffected","version":"5.9.3","versionType":"semver"}]},{"defaultStatus":"unaffected","ecosystem":"npm","packageName":"devalue","product":"devalue","source":"OSV GHSA-hx4r-w6wj-j8fg","vendor":"","versions":[{"events":[{"introduced":"0"},{"fixed":"5.9.3"}],"lessThan":"5.9.3","status":"affected","version":"0","versionType":"semver"}]}],"cveId":"CVE-2026-123566","cwes":["CWE-400"],"description":"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.","epss":{"date":"2026-11-08","percentile":0.28071,"score":0.00343},"exploits":[],"kev":null,"metrics":[{"score":8.7,"severity":"high","source":"CNA: VulnCheck","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","version":"4.0"},{"score":7.5,"severity":"high","source":"CNA: VulnCheck","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},{"score":8.7,"severity":"high","source":"NVD: disclosure@vulncheck.com","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","version":"4.0"},{"score":7.5,"severity":"high","source":"NVD: disclosure@vulncheck.com","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}],"modifiedAt":1794232606305,"publishedAt":1794101885159,"references":[{"source":"CNA: VulnCheck","tags":["vendor-advisory"],"url":"https://github.com/sveltejs/devalue/security/advisories/GHSA-hx4r-w6wj-j8fg"},{"source":"CNA: VulnCheck","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/devalue-before-5.9.3-cpu-amplification-denial-of-service-via-uneval"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/sveltejs/devalue/security/advisories/GHSA-hx4r-w6wj-j8fg"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://www.vulncheck.com/advisories/devalue-before-5.9.3-cpu-amplification-denial-of-service-via-uneval"},{"source":"OSV / GitHub Security Advisories","tags":["advisory"],"url":"https://github.com/advisories/GHSA-hx4r-w6wj-j8fg"},{"source":"OSV / GitHub Security Advisories","tags":["osv"],"url":"https://osv.dev/vulnerability/GHSA-hx4r-w6wj-j8fg"}],"remediation":[{"kind":"fix","source":"OSV GHSA-hx4r-w6wj-j8fg","text":"devalue (npm): OSV reports a fixed version 5.9.3. Check the advisory for supported release branches.","url":"https://github.com/advisories/GHSA-hx4r-w6wj-j8fg"}],"revision":"e40eed62b916ea4cb1cc9c749f3d87ab3ee5614eb118af03978e7485927d7ebe","sources":[{"modifiedAt":1794232606305,"name":"CNA: VulnCheck","retrievedAt":1794233355999,"url":"https://www.cve.org/CVERecord?id=CVE-2026-123566"},{"modifiedAt":1794104209197,"name":"NVD","retrievedAt":1794118575858,"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-123566"},{"modifiedAt":1794135371387,"name":"OSV / GitHub Security Advisories","retrievedAt":1794233356404,"url":"https://osv.dev/vulnerability/GHSA-hx4r-w6wj-j8fg"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1794233356274,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-123566"}],"ssvc":{"assessedAt":1794232575132,"automatable":"yes","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"partial"},"status":"published","title":"Devalue before 5.9.3 CPU Amplification Denial of Service via uneval","updatedAt":1794233356404}