CVE-2026-45286
Nextcloud: Calendar app leaked user identifiers via attendee suggestion endpoint
Vexday Risk Score
13Low
SSVC decision (CISA)
Track
No exploitation signal → monitor
CVSS 4.3EPSS 0.3%KEV nãoPoC —Nuclei —Metasploit —Patch —
Lifecycle
01 Jun 2026Published on NVD
Recommendation: Monitor — no exploitation signal at the moment.
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.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Affected products
nextcloud · security-advisoriesWant to know if your infrastructure is exposed to this?
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