GHSA-9643-4qgh-g8mx
elysia has Inefficient Algorithmic Complexity and Interpretation Conflict
Packages
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.
- https://github.com/elysiajs/elysia/security/advisories/GHSA-9643-4qgh-g8mx
- https://nvd.nist.gov/vuln/detail/CVE-2026-56669
- https://github.com/elysiajs/elysia/commit/8358ff9efbcedf9534995f5977f26b9ceab59329
- https://gist.github.com/jviide/ea040eabe7bac058326174e2cd42dfd9
- https://github.com/elysiajs/elysia
- https://github.com/elysiajs/elysia/releases/tag/1.4.29