CVE-2026-45286

Summary

Nextcloud is an open source content collaboration platform. From versions 5.5.13 to before 5.5.17, and 6.2.0 to before 6.2.3, an authenticated user can enumerate users on the same Nextcloud instance by using the Calendar app's endpoint for suggesting attendees. The sharing restrictions, applied to other endpoints, were not effective here. This issue has been patched in versions 5.5.17 and 6.2.3.

Affected Software

VendorProductVersion RangeStatus
nextcloudsecurity-advisories>= 5.5.13, < 5.5.17affected
nextcloudsecurity-advisories>= 6.2.0, < 6.2.3affected

Weaknesses

  • CWE-200: CWE-200: Exposure of Sensitive Information to an Unauthorized Actor

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References