{"id":"CVE-2026-123564","title":"Sveltejs devalue before 5.9.3 Memory Exhaustion via uneval Sparse Arrays","summary":"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 …","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-770"],"vendor":"sveltejs","product":"devalue","affected":["devalue >= 1.0.0 < 5.9.3"],"published":"2026-11-08","updated":"2026-11-08","sourceUpdated":"2026-11-08T01:38:03.802Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-123564","references":[{"url":"https://github.com/sveltejs/devalue/security/advisories/GHSA-wf3x-273g-mvxv","label":"GitHub Security Advisory (GHSA-wf3x-273g-mvxv)"},{"url":"https://www.vulncheck.com/advisories/sveltejs-devalue-before-5.9.3-memory-exhaustion-via-uneval-sparse-arrays","label":"VulnCheck Advisory: Sveltejs devalue before 5.9.3 Memory Exhaustion via uneval Sparse Arrays"}],"tags":["cve.org"],"ingestedAt":"2026-11-08T02:43:18.661Z","slug":"CVE-2026-123564","body":"## Overview\n\nSveltejs 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.\n\n## Affected\n\n- `devalue >= 1.0.0 < 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":[]}