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TI-2023-17990 Aliases CVE-2023-35928

Nextcloud user scoped external storage can be used to gather credentials of other users

Priority MEDIUM 42CWE-274Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA.

Summary

Nextcloud Server is a space for data storage on Nextcloud, a self-hosted productivity playform. In NextCloud Server versions 25.0.0 until 25.0.7 and 26.0.0 until 26.0.2 and Nextcloud Enterprise Server versions 19.0.0 until 19.0.13.9, 20.0.0 until 20.0.14.14, 21.0.0 until 21.0.9.12, 22.0.0 until 22.2.10.12, 23.0.0 until 23.0.12.7, 24.0.0 until 24.0.12.2, 25.0.0 until 25.0.7, and 26.0.0 until 26.0.2, a user could use this functionality to get access to the login credentials of another user and take over their account. This issue has been patched in Nextcloud Server versions 25.0.7 and 26.0.2 and NextCloud Enterprise Server versions 19.0.13.9, 20.0.14.14, 21.0.9.12, 22.2.10.12, 23.0.12.7, 24.0.12.2, 25.0.7, and 26.0.2. Three workarounds are available. Disable app files_external. Change config setting "Allow users to mount external storage" to disabled in "Administration" > "External storage" settings `…/index.php/settings/admin/externalstorages`. Change config setting to disallow users to create external storages in "Administration" > "External storage" settings `…/index.php/settings/admin/externalstorages` with the types FTP, Nextcloud, SFTP, and/or WebDAV.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00981 62nd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

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-advisoriesNextcloud Enterprise Server >= 19.0.0, < 19.0.13.9; Nextcloud Enterprise Server >= 20.0.0.0, < 20.0.14.14; Nextcloud Enterprise Server >= 21.0.0.0, < 21.0.9.12; Nextcloud Enterprise Server >= 22.0.0.0, < 22.2.10.12; Nextcloud Enterprise Server >= 23.0.0.0, < 23.0.12.7; Nextcloud Enterprise Server >= 24.0.0.0, < 24.0.12.2; Nextcloud Enterprise Server >= 25.0.0, < 25.0.7 ; Nextcloud Enterprise Server >= 26.0.0, < 26.0.2; Nextcloud Server >= 25.0.0, < 25.0.7; Nextcloud Server >= 26.0.0, < 26.0.2—No fix listedCNA
  • security-advisories Vendornextcloud Affected Nextcloud Enterprise Server >= 19.0.0, < 19.0.13.9; Nextcloud Enterprise Server >= 20.0.0.0, < 20.0.14.14; Nextcloud Enterprise Server >= 21.0.0.0, < 21.0.9.12; Nextcloud Enterprise Server >= 22.0.0.0, < 22.2.10.12; Nextcloud Enterprise Server >= 23.0.0.0, < 23.0.12.7; Nextcloud Enterprise Server >= 24.0.0.0, < 24.0.12.2; Nextcloud Enterprise Server >= 25.0.0, < 25.0.7 ; Nextcloud Enterprise Server >= 26.0.0, < 26.0.2; Nextcloud Server >= 25.0.0, < 25.0.7; Nextcloud Server >= 26.0.0, < 26.0.2 Fixed in — No fix listed CNA

CPE configurations NVD · 5

CPEVersionsRoleVendor
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:*19.0.0 to before 19.0.13.9; 20.0.0 to before 20.0.14.14; 21.0.0 to before 21.0.9.12; 22.0.0 to before 22.2.10.12; 23.0.0 to before 23.0.12.7; 24.0.0 to before 24.0.12.2Vulnerablenextcloud
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:*25.0.0 to before 25.0.7Vulnerablenextcloud
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:*25.0.0 to before 25.0.7Vulnerablenextcloud
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:*26.0.0 to before 26.0.2Vulnerablenextcloud
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:*26.0.0 to before 26.0.2Vulnerablenextcloud
  • cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* Versions 19.0.0 to before 19.0.13.9; 20.0.0 to before 20.0.14.14; 21.0.0 to before 21.0.9.12; 22.0.0 to before 22.2.10.12; 23.0.0 to before 23.0.12.7; 24.0.0 to before 24.0.12.2 Vulnerable ·nextcloud
  • cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:* Versions 25.0.0 to before 25.0.7 Vulnerable ·nextcloud
  • cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* Versions 25.0.0 to before 25.0.7 Vulnerable ·nextcloud
  • cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:* Versions 26.0.0 to before 26.0.2 Vulnerable ·nextcloud
  • cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* Versions 26.0.0 to before 26.0.2 Vulnerable ·nextcloud

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2023-35928

References

Advisory 2

Other 1

  • 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
  • TI-2025-37238 Cross-site scripting in Nextcloud CVSS 3.1MEDIUM 6.4
  • TI-2023-11086 nextcloud vulnerable to Uncontrolled Resource Consumption CVSS 3.1MEDIUM 6.5
  • TI-2022-18738 Exception logging in Sharepoint app reveals clear-text connection details CVSS 3.1MEDIUM 6.5
See all 188 →

Sources

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