CVE-2026-91972

Vikunja before 2.6.0 Authentication Bypass via Unthrottled API

Published Sep 15, 2026 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed
Description
Vikunja versions before 2.6.0 fail to apply rate limiting to /api/v2 public authentication endpoints including login, register, password-reset, and OAuth token routes. Remote unauthenticated attackers can perform unbounded credential guessing, account enumeration, and password-reset flooding attacks without throttling restrictions.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-6rvj-qwjf-3m4q Vikunja: Every /api/v2 pre-auth endpoint is unthrottled on a stock install while its /api/v1 twin is rate limited
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Go-vikunja
Go-vikunja vikunja
Vendors & Products Go-vikunja
Go-vikunja vikunja
Type Values Removed Values Added
Description Vikunja versions before 2.6.0 fail to apply rate limiting to /api/v2 public authentication endpoints including login, register, password-reset, and OAuth token routes. Remote unauthenticated attackers can perform unbounded credential guessing, account enumeration, and password-reset flooding attacks without throttling restrictions.
Title Vikunja before 2.6.0 Authentication Bypass via Unthrottled API
First Time appeared Vikunja
Vikunja vikunja
Weaknesses CWE-307
CPEs cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:*
Vendors & Products Vikunja
Vikunja vikunja
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Sep 17, 2026, 3:12 PM
Reserved
Sep 15, 2026, 11:09 AM
Status
Deferred
Published
Sep 15, 2026, 4:17 PM
Modified
Sep 17, 2026, 4:18 PM