What’s Vulnerable › Vulnerabilities

CVE-2023-35172: Nextcloud Server password reset endpoint is not brute force protected

• Severity: critical (CVSS 9.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.9% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2023-06-23 · updated 2026-06-17
• Weakness: CWE-307

Description

NextCloud Server and NextCloud Enterprise Server provide file storage for Nextcloud, a self-hosted productivity platform. In NextCloud Server versions 25.0.0 until 25.0.7 and 26.0.0 until 26.0.2 and Nextcloud Enterprise Server versions 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, an attacker can bruteforce the password reset links. Nextcloud Server n 25.0.7 and 26.0.2 and Nextcloud Enterprise Server 21.0.9.12, 22.2.10.12, 23.0.12.7, 24.0.12.2, 25.0.7, and 26.0.2 contain a patch for this issue. No known workarounds are available.

Affected products

• Nextcloud Server: from 21.0.0 before 21.0.9.12; from 22.0.0 before 22.2.10.12; from 23.0.0 before 23.0.12.7; from 24.0.0 before 24.0.12.2; from 25.0.0 before 25.0.7; from 26.0.0 before 26.0.2 — fixed in 21.0.9.12, 22.2.10.12, 23.0.12.7, 24.0.12.2, 25.0.7, 26.0.2

How to fix

Upgrade to a fixed version: Nextcloud Server 21.0.9.12, 22.2.10.12, 23.0.12.7, 24.0.12.2. Check the vendor advisory for mitigations.

References

• https://github.com/nextcloud/security-advisories/security/advisories/GHSA-mjf5-p765-qmr6
• https://github.com/nextcloud/server/pull/38267
• https://hackerone.com/reports/1987062
• https://github.com/nextcloud/security-advisories/security/advisories/GHSA-mjf5-p765-qmr6
• https://github.com/nextcloud/server/pull/38267
• https://hackerone.com/reports/1987062

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