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TI-2026-33069 Aliases CVE-2026-45264

Nextcloud: ACL Rename Permission Bypass in Team Folders Allows Unauthorized File Renames

Priority LOW 19CWE-284Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
None · Low · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-284.

Summary

Nextcloud is an open source content collaboration platform. From versions 17.0.0 to before 17.0.15, 18.0.0 to before 18.1.12, 19.0.0 to before 19.1.16, 20.0.0 to before 20.1.11, and 21.0.0 to before 21.0.4, a user with READ and CREATE permission, but no UPDATE permission for a team folder can rename files in the team folder. This issue has been patched in versions 17.0.15, 18.1.12, 19.1.16, 20.1.11, and 21.0.4.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00229 13th percentileScored 2026-11-07
Fix Fixed security-advisories (nextcloud): 17.0.15, 18.1.12, 19.1.16 +2

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
nextcloudsecurity-advisories17.0.0 to before 17.0.15; 18.0.0 to before 18.1.12; 19.0.0 to before 19.1.16; 20.0.0 to before 20.1.11; 21.0.0 to before 21.0.417.0.15, 18.1.12, 19.1.16, 20.1.11, 21.0.4Patch availableCNA
  • security-advisories Vendornextcloud Affected 17.0.0 to before 17.0.15; 18.0.0 to before 18.1.12; 19.0.0 to before 19.1.16; 20.0.0 to before 20.1.11; 21.0.0 to before 21.0.4 Fixed in 17.0.15, 18.1.12, 19.1.16, 20.1.11, 21.0.4 Patch available CNA

Remediation

  • Fix · CNA security-advisories (nextcloud) Fixed in 17.0.15, 18.1.12, 19.1.16, 20.1.11, 21.0.4

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-45264

References

Other 3

  • TI-2026-18211 Windmill < 1.615.0 Operator Role Missing Authorization Checks RCE CVSS 4.0HIGH 8.7
  • TI-2023-14838 NextCloud Cookbook's pull-checks.yml workflow is vulnerable to OS Command Injection CVSS 3.1HIGH 8.8
  • TI-2022-08650 Command Injection in Appointment Emails for Nextcloud Calendar CVSS 3.1CRITICAL 9.8
  • TI-2023-20855 Users can delete external storage mount points CVSS 3.1HIGH 7.7
  • TI-2023-11091 Nextcloud download permissions can be changed by resharer CVSS 3.1HIGH 7.5
  • TI-2023-10624 Nextcloud Server vulnerable to SSRF via filter bypass due to lax checking on IPs CVSS 3.1MEDIUM 5.3
See all 401 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences