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TI-2023-20853 Aliases CVE-2023-39960

Nextcloud Server has improper restriction of excessive authentication attempts on WebDAV endpoint

Priority LOW 34CWE-307Published · Updated

Key facts

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

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-307.

Summary

Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. In Nextcloud Server starting with 25.0.0 and prior to 25.09 and 26.04; as well as Nextcloud Enterprise Server starting with 22.0.0 and prior to 22.2.10.14, 23.0.12.9, 24.0.12.5, 25.0.9, and 26.0.4; missing protection allows an attacker to brute force passwords on the WebDAV API. Nextcloud Server 25.0.9 and 26.0.4 and Nextcloud Enterprise Server 22.2.10.14, 23.0.12.9, 24.0.12.5, 25.0.9, and 26.0.4 contain patches for this issue. No known workarounds are available.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00709 53rd percentileScored 2026-11-07
Fix Fixed security-advisories (nextcloud): 22.2.10.14, 23.0.12.9, 24.0.12.5 +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-advisories22.0.0 to before 22.2.10.14; 23.0.0 to before 23.0.12.9; 24.0.0 to before 24.0.12.5; 25.0.0 to before 25.0.9; 26.0.0 to before 26.0.422.2.10.14, 23.0.12.9, 24.0.12.5, 25.0.9, 26.0.4Patch availableCNA
  • security-advisories Vendornextcloud Affected 22.0.0 to before 22.2.10.14; 23.0.0 to before 23.0.12.9; 24.0.0 to before 24.0.12.5; 25.0.0 to before 25.0.9; 26.0.0 to before 26.0.4 Fixed in 22.2.10.14, 23.0.12.9, 24.0.12.5, 25.0.9, 26.0.4 Patch available CNA

CPE configurations NVD · 5

CPEVersionsRoleVendor
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:*22.0.0 to before 22.2.10.14; 23.0.0 to before 23.0.12.9; 24.0.0 to before 24.0.12.5Vulnerablenextcloud
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:*25.0.0 to before 25.0.9Vulnerablenextcloud
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:*25.0.0 to before 25.0.9Vulnerablenextcloud
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:*26.0.0 to before 26.0.4Vulnerablenextcloud
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:*26.0.0 to before 26.0.4Vulnerablenextcloud
  • cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* Versions 22.0.0 to before 22.2.10.14; 23.0.0 to before 23.0.12.9; 24.0.0 to before 24.0.12.5 Vulnerable ·nextcloud
  • cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:* Versions 25.0.0 to before 25.0.9 Vulnerable ·nextcloud
  • cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* Versions 25.0.0 to before 25.0.9 Vulnerable ·nextcloud
  • cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:* Versions 26.0.0 to before 26.0.4 Vulnerable ·nextcloud
  • cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* Versions 26.0.0 to before 26.0.4 Vulnerable ·nextcloud

Remediation

  • Fix · CNA security-advisories (nextcloud) Fixed in 22.2.10.14, 23.0.12.9, 24.0.12.5, 25.0.9, 26.0.4

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-2023-39960
  2. 2026-10-14 EPSS moved to the 50th–90th percentile

References

Patch 1

Advisory 2

  • 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