CVE-2026-123564
Sveltejs devalue before 5.9.3 Memory Exhaustion via uneval Sparse Arrays
CVSS Score
7.5
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-770 |
| Vendor | sveltejs |
| Product | devalue |
| Published | Nov 8, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
sveltejs / devalue
1.0.0 < 5.9.3
References
Credits
elliott-with-the-longest-name-on-github