What’s Vulnerable › Vulnerabilities

CVE-2023-35171: Nextcloud Server vulnerable to open redirect on "Unsupported browser" warning

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2023-06-23 · updated 2026-06-17
• Weakness: CWE-601

Description

NextCloud Server and NextCloud Enterprise Server provide file storage for Nextcloud, a self-hosted productivity platform. Starting in version 26.0.0 and prior to version 26.0.2, an attacker could supply a URL that redirects an unsuspecting victim from a legitimate domain to an attacker's site. Nextcloud Server and Nextcloud Enterprise Server 26.0.2 contain a patch for this issue. No known workarounds are available.

Affected products

• Nextcloud Server: from 26.0.0 before 26.0.2 — fixed in 26.0.2

How to fix

Upgrade to a fixed version: Nextcloud Server 26.0.2. Check the vendor advisory for mitigations.

References

• https://github.com/nextcloud/security-advisories/security/advisories/GHSA-h353-vvwv-j2r4
• https://github.com/nextcloud/server/pull/38194
• https://hackerone.com/reports/1977222
• https://github.com/nextcloud/security-advisories/security/advisories/GHSA-h353-vvwv-j2r4
• https://github.com/nextcloud/server/pull/38194
• https://hackerone.com/reports/1977222

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