CVE-2026-80199

EUVD-2026-66221
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
VulnCheckCNA
3.7 LOW
NETWORK
HIGH
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 15.89%
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
kimaikimai
𝑥
< 2.54.0
CNA
Common Weakness Enumeration
References
https://github.com/kimai/kimai/security/advisories/GHSA-jrc6-fmhw-fpq2
https://www.vulncheck.com/advisories/kimai-before-2.54.0-username-enumeration-via-timing-oracle