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TI-2026-33079 Aliases CVE-2026-45278

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

Priority LOW 27CWE-601Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Spoofing
Confidentiality · integrity · availability
Low · Low · None
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-601.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00232 14th percentileScored 2026-11-07
Fix Fixed security-advisories (nextcloud): 8.2.2

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-advisories6.1.0 to before 8.2.28.2.2Patch availableCNA
  • security-advisories Vendornextcloud Affected 6.1.0 to before 8.2.2 Fixed in 8.2.2 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:nextcloud:user_oidc:*:*:*:*:*:*:*:*6.1.0 to before 8.2.2Vulnerablenextcloud
  • cpe:2.3:a:nextcloud:user_oidc:*:*:*:*:*:*:*:* Versions 6.1.0 to before 8.2.2 Vulnerable ·nextcloud

Remediation

  • Fix · CNA security-advisories (nextcloud) Fixed in 8.2.2

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-45278

References

Patch 1

Advisory 1

Other 1

  • TI-2023-15378 Nextcloud user_oidc app is missing brute force protection CVSS 3.1CRITICAL 9.8
  • TI-2026-33084 Nextcloud: Wrong condition in the User OIDC app's LdapService allowed deleted LDAP users to authenticate CVSS 3.1HIGH 8.8
  • TI-2023-20847 user_oidc app stores client secret unencrypted in database CVSS 3.1HIGH 8.1
  • TI-2024-24824 Nextcloud user_oidc app's ID4me feature is available even when disabled CVSS 3.1MEDIUM 6.3
  • TI-2024-35183 Nextcloud User OIDC has an open redirection when logging in with User OIDC CVSS 3.1MEDIUM 6.1
  • TI-2024-25203 Nextcloud user_oidc's ID4me does not validate signature or expiration CVSS 3.1MEDIUM 5.4
See all 8 →

Sources

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