PatchTheCVECVE-2026-48611: Improper authentication checks in the OAuth implementation allow account hijacking even when OAuth is not conf
CVE-2026-48611 is a critical-severity flaw (CVSS 9.8) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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.
Why this priority
- Critical severity
- EPSS top 10%: very likely to be exploited
- CISA SSVC: automatable with total technical impact
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 9.8 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 3.9% (top 10%) |
| CISA exploited list | No |
| Weakness | CWE-287 |
| Published | 2026-06-12 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Exact fixes by distribution
Public exploits and detection
Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.
- GitHub PoC: lxdwnpiper/CVE-2026-48611-phpBB (0 stars)
- GitHub PoC: Ethicalgrey/phpBB-CVE-2026-48611 (0 stars)
- Nuclei scan template: phpBB < 3.3.17 - Authentication Bypass
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-48611?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-48611 being exploited?
CVE-2026-48611 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-48611 affect?
CVE-2026-48611 affects affected software. Severity is critical (CVSS 9.8). 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.
How urgent is CVE-2026-48611?
Priority 65/100. Critical severity; EPSS top 10%: very likely to be exploited; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action