CVE-2026-48611

OAuth Authentication Bypass Allows Account Hijacking in phpBB

Published Jun 12, 2026 CVSS 3.0 · 9.8 Critical EPSS 3.9% KEV · Not listed
Description
Improper authentication checks in the OAuth implementation allow account hijacking even when OAuth is not configured or enabled leading to unauthorized access in default installations.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
Title OAuth Authentication Bypass Allows Account Hijacking in phpBB
Type Values Removed Values Added
Title OAuth Authentication Bypass Allowing Account Hijacking in phpBB
Type Values Removed Values Added
Title OAuth Authentication Bypass Allowing Account Hijacking in phpBB
Type Values Removed Values Added
Title Account Hijacking via Unconditional OAuth Authentication Bypass in phpBB
Type Values Removed Values Added
Title Account Hijacking via Unconditional OAuth Authentication Bypass in phpBB
Type Values Removed Values Added
Title OAuth Authentication Bypass Enables Account Hijacking in phpBB
Type Values Removed Values Added
Title OAuth Authentication Bypass Enables Account Hijacking in phpBB
Type Values Removed Values Added
Title Improper Authentication in phpBB OAuth Enables Account Hijacking
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Phpbb
Phpbb phpbb
Vendors & Products Phpbb
Phpbb phpbb
Type Values Removed Values Added
Title Improper Authentication in phpBB OAuth Enables Account Hijacking
Type Values Removed Values Added
Description Improper authentication checks in the OAuth implementation allow account hijacking even when OAuth is not configured or enabled leading to unauthorized access in default installations.
Weaknesses CWE-287
References
Metrics cvssV3_0

{'score': 9.8, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
hackerone
Published
Updated
Jun 12, 2026, 12:55 PM
Reserved
May 22, 2026, 3:00 PM
Status
Deferred
Published
Jun 12, 2026, 4:17 AM
Modified
Jun 17, 2026, 10:55 AM