TI-2026-55440 Aliases CVE-2026-80199 GHSA-p6f7-72pm-r6j9

Kimai before 2.54.0 Username Enumeration via Timing Oracle

MEDIUM 61CWE-208Published 2026-08-25 · Updated 2026-10-08

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: High
Attack requirements: Present
Impact type: Information disclosure
Confidentiality · integrity · availability: Low · None · None
Fix status: Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-208.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00308 23rd percentileScored 2026-11-07

Fix Fixed kimai (kimai): 2.54.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
kimai	kimai	before 2.54.0	2.54.0	Patch available	CNA

kimai Vendorkimai Affected before 2.54.0 Fixed in 2.54.0 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:a:kimai:kimai::::::::	—	—	kimai

cpe:2.3:a:kimai:kimai:*:*:*:*:*:*:*:* Versions — — ·kimai

Remediation

Fix · CNA kimai (kimai) Fixed in 2.54.0

Timeline

2026-10-02 Threatist record created from CVE-2026-80199
2026-10-03 Alias added: GHSA-p6f7-72pm-r6j9

References

Advisory 1

GitHub Security Advisory (GHSA-jrc6-fmhw-fpq2)

TI-2023-30240 Kimai 1.30.10 SameSite Cookie Vulnerability Session Hijacking CVSS 4.0HIGH 8.5
TI-2026-55437 Kimai before 2.58.0 Authentication Bypass via Password Reset Link CVSS 4.0HIGH 8.7
TI-2026-55443 Kimai before 2.56.0 Authorization Bypass via TimesheetVoter CVSS 4.0CRITICAL 9.3
TI-2026-22900 Kimai: API invoice endpoint missing customer-level access control (IDOR) CVSS 3.1MEDIUM 6.5
TI-2026-37927 Incorrect authorization in kimai CVSS 4.0MEDIUM 6.3
TI-2026-30580 Kimai: Formula Injection via tag names in XLSX export CVSS 4.0MEDIUM 5.4

See all 46 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences