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GHSA-9643-4qgh-g8mx

elysia has Inefficient Algorithmic Complexity and Interpretation Conflict

Source: GitHub Advisory Database (reviewed) High CVE-2026-56669

Packages

EcosystemPackageAffectedFixed in
npm elysia < 1.4.29 1.4.29

Details

As written in the advisory (Markdown source, shown as plain text).

Elysia v1.4.28 is vulnerable to denial-of-service attacks due to CPU exhaustion in the form data normalization code. Elysia uses `getAll` to retrieve value from FormData. It is called directly relative to the total number of key-value pairs in the form data. The total amount of work the for loop has to do grows quadratically, so doubling the number of unique key-value pairs quadruples the amount of work. In the above PoC, each .getAll call scans through all of the `n` key-value pairs in the form data. Because there are `n` unique keys in the form data, there are .getAll calls, so in total the form data normalizer has to scan `n` x `n` key-value pairs. ### Impact Endpoints using `multipart/form-data` ### Patches 1.4.29 ### Workarounds no 100% confirm workaround beside updating the patch

References

External links from the advisory. They lead to third-party sites.