CVE-2026-48611
CriticalExploitedImproper authentication checks in the OAuth implementation allow account hijacking even when OAuth is not configured or enabled leading to unauthorized access in default installations.
Published Jun 12, 2026 · Updated Jun 12, 2026 · Also known as EUVD-2026-36375, GHSA-24pr-8ggp-h88c
Key Facts
Patch immediately- CVE-2026-48611 is a critical-severity vulnerability (CVSS 9.8 v3) affecting phpBB.
- It is exploited in the wild, listed in Industry KEV feed, CIRCL KEV since Jul 20, 2026. No public exploit code is known.
- EPSS estimates a 2.9% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3
9.8
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
2.9%
Higher than 86.6% of all scored CVEs
Exploited in the wild
Yes
2 catalog listings
Public exploit code
None known
Get the full CVE-2026-48611 brief as a PDF
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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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Jul 20, 2026 | n/a | Not reported |
| CIRCL KEV | Jul 20, 2026 | n/a | Not reported |
Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Affected Products
2 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| phpBB | >= 3.3.0 | n/a |
Timeline
Publicly disclosed
Jun 12, 2026
Added to Industry KEV feed
Jul 20, 2026
Added to CIRCL KEV
Jul 20, 2026
Weakness Type
- CWE-287 Improper Authentication
References
FAQ
Common Questions.
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: phpBB versions >= 3.3.0. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed, CIRCL KEV since Jul 20, 2026.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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