cvedb.io
CVE-2025-27143
MEDIUM · CVSS 6.1
EPSS exploitation probability: 0%
Published 2025-02-24T23:15:11.160 · Last modified 2026-06-17T09:03:05.560

Summary

Better Auth is an authentication and authorization library for TypeScript. Prior to version 1.1.21, the application is vulnerable to an open redirect due to improper validation of the callbackURL parameter in the email verification endpoint and any other endpoint that accepts callback url. While the server blocks fully qualified URLs, it incorrectly allows scheme-less URLs. This results in the browser interpreting the URL as a fully qualified URL, leading to unintended redirection. An attacker can exploit this flaw by crafting a malicious verification link and tricking users into clicking it. Upon successful email verification, the user will be automatically redirected to the attacker's website, which can be used for phishing, malware distribution, or stealing sensitive authentication toke

Affected products

better-auth — better_auth

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.