CVE-2026-45278

Nextcloud: Open Redirect in user_oidc login flow via protocol-relative URL bypass

CVSS 3.3 LOWEPSS 0.2%CWE-601

Vexday Risk Score

8Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 3.3EPSS 0.2%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

01 Jun 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

Nextcloud is an open source content collaboration platform. From version 6.1.0 to before version 8.2.2, an attacker can craft links that would redirect users to another website, when the victim uses the attackers link to log in via user OIDC. This issue has been patched in version 8.2.2.

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Affected products

nextcloud · security-advisories

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References

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-8wjr-5cg8-4w73 https://github.com/nextcloud/user_oidc/pull/1273 https://hackerone.com/reports/3464925