Vulnerability · Published Jun 12, 2026 · Assigned by hackerone
CVE-2026-48611
Critical 9.8
In plain English
A critical-severity improper authentication in phpBB from phpBB. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 3.9% (higher than 90% of all known vulnerabilities). Ready-made attack tooling exists: Nuclei, public proof-of-concept code.
Severity (CVSS 3.0)9.8Critical
Exploit odds (30 days)3.9%top 9.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack tooling2Nuclei, Public PoC
Official 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.
Affected products (as reported)
Weakness: CWE-287 · Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H