Vikunja before 2.6.0 contains an authentication bypass vulnerability in CalDAV BasicAuth endpoints that lack rate limiting protection. Remote unauthenticated attackers can issue unbounded credential-guessing requests against /dav, /.well-known, and /feeds routes to bypass the instance's anti-brute-force controls and compromise password-only accounts.

Project Subscriptions

Vendors Products
Go-vikunja Subscribe
Vikunja Subscribe
Vikunja Subscribe
Vikunja Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 15 Sep 2026 21:30:00 +0000

Type Values Removed Values Added
First Time appeared Go-vikunja
Go-vikunja vikunja
Vendors & Products Go-vikunja
Go-vikunja vikunja

Tue, 15 Sep 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

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


Tue, 15 Sep 2026 15:30:00 +0000

Type Values Removed Values Added
Description Vikunja before 2.6.0 contains an authentication bypass vulnerability in CalDAV BasicAuth endpoints that lack rate limiting protection. Remote unauthenticated attackers can issue unbounded credential-guessing requests against /dav, /.well-known, and /feeds routes to bypass the instance's anti-brute-force controls and compromise password-only accounts.
Title Vikunja before 2.6.0 Authentication Bypass via CalDAV BasicAuth
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'}


Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-09-15T15:55:04.161Z

Reserved: 2026-09-15T11:09:54.873Z

Link: CVE-2026-91973

cve-icon Vulnrichment

Updated: 2026-09-15T15:54:38.336Z

cve-icon NVD

Status : Received

Published: 2026-09-15T16:17:54.230

Modified: 2026-09-15T16:17:54.230

Link: CVE-2026-91973

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-15T21:15:14Z

Weaknesses