User Enumeration Vulnerability in Vikunja by Vikunja
CVE-2026-91981

5.3MEDIUM

Key Information:

Vendor

Go-vikunja

Status
Vikunja
Vendor
CVE Published:
15 September 2026

What is CVE-2026-91981?

In Vikunja versions prior to 2.6.0, an issue has been identified involving improper validation of link-share tokens within the v2 API's user search endpoints. This vulnerability allows attackers who possess a read-only share link to enumerate users associated with projects via the projects endpoint. Furthermore, they can confirm the existence of arbitrary usernames through the global search endpoint, potentially exposing sensitive user information and compromising data privacy.

Affected Version(s)

vikunja 0 < 2.6.0

vikunja 2.6.0

References

https://github.com/go-vikunja/vikunja/security/advisories...
vendor-advisory
https://www.vulncheck.com/advisories/vikunja-before-2.6.0...
third-party-advisory

CVSS V4

Score:
5.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

0xcelien
.