CVE-2026-91973
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.
Published:Sep 15, 2026
Last Modified:Sep 15, 2026
EPS:Sep 15, 2026
EPSS Score:
CVSS Score:7.5
Affected Products
Vendor
Product
Action
Vendor
Go-vikunja
Product
Vikunja
Go-vikunja
Vikunja
Vendor
Vikunja
Product
Vikunja
Vikunja
Vikunja
Exploits
No exploit reference
Common Weakness Enumeration
Common Attack Pattern Enumeration and Classification (CAPEC)
Related CVEs
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
