# CVE-2026-91980

## Summary

- **CVE ID:** CVE-2026-91980
- **Severity:** MEDIUM
- **CVSS Score:** 5.3 (CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N)
- **CWE:** CWE-200
- **Published:** Sep 15, 2026
- **Last Modified:** Sep 15, 2026

## Description

vikunja before 2.6.0 fails to validate team access when attaching teams to projects, allowing authenticated users to enumerate all teams and members. Attackers can attach arbitrary team IDs via the project teams endpoint to retrieve complete team rosters including member names and admin flags for unauthorized teams.

## Affected Products

- go-vikunja — vikunja (0)
- go-vikunja — vikunja (2.6.0)

## References

- [CNA](https://github.com/go-vikunja/vikunja/security/advisories/GHSA-39p5-2wrr-xh29)
- [CNA](https://www.vulncheck.com/advisories/vikunja-before-2.6.0-team-enumeration-via-project-share)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.27%
- **EPSS Percentile:** 19.5

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._