v8n is a javascript validation library. Versions of v8n prior to 1.5.1 were found to have an inefficient regular expression complexity in the `lowercase()` and `uppercase()` regex which could lead to a denial of service attack. In testing of the `lowercase()` function a payload of 'a' + 'a'.repeat(i) + 'A' with 32 leading characters took 29443 ms to execute. The same issue happens with uppercase(). Users are advised to upgrade. There are no known workarounds for this issue.
https://huntr.dev/bounties/2d92f644-593b-43b4-bfd1-c8042ac60609/
https://github.com/imbrn/v8n/security/advisories/GHSA-xrx9-gj26-5wx9
https://github.com/imbrn/v8n/commit/92393862156fad190c05ec3f6e2bc73308dcd2f9