Kimai before 2.54.0 contains a timing oracle vulnerability in TokenAuthenticator that allows unauthenticated attackers to enumerate valid usernames via X-AUTH-USER header. Attackers can measure response time differences when the password hasher runs only for existing users, enabling username enumeration with no login throttling protection.
{
"cwe_ids": [
"CWE-208"
],
"cna_assigner": "VulnCheck",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80199.json"
}