CVSS 4.0
8.7 highCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:NCVE-2026-91973
High (8.7). EPSS 0.7% chance of exploitation in the next 30 days. Fixed in code.vikunja.io/api 2.6.0.
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.
Severity
CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N- EPSS
- 0.7% chance of exploitation in the next 30 days; higher than 52% of CVEs (scores of 2026-10-31)
- CWE
- CWE-307
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-m469-88xx-8rx2 | Go | code.vikunja.io/api | <2.6.0 | 2.6.0 |
| GO-2026-6737 | Go | code.vikunja.io/api | all versions | no fix published |