GitHub Advisoryadvisory · npm
GHSA-wf3x-273g-mvxv devalue: Sparse arrays emitted by uneval cause eager allocation when evaluated
LOW
Official page ↗
- Ecosystem
- npm
- Packages
- devalue
- Severity
- Low
- CVSS vector
- CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:N/SI:N/SA:L
- Weaknesses
- CWE-400, CWE-789
- Reviewed
- 2026-10-01
Affected packages
• npm devalue: >= 1.0.0, < 5.9.3 → fixed in 5.9.3
Description
Evaluating legitimate `uneval` output for a sparse array can allocate memory proportional to its declared length. A tiny serialized value can therefore cause large memory allocation in a consuming browser/runtime. This occurs during evaluation of generated code, not in default `parse` sparse-array construction.
You would only be affected by this if you were serializing very large sparse arrays and then evaluating the results. In the general use case for `uneval` of sending data to the client, the worst that could happen is the browser tab running out of memory.