Quick answers
- Is CVE-2026-48611 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-48611 being exploited in the wild.
- How severe is CVE-2026-48611?
- Critical severity, with a CVSS score of 9.8, published 12 June 2026.
- Which products and versions are affected?
- phpBB phpBB.
- Is there a fix for CVE-2026-48611?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-48611 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-48611?
- Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A vulnerability classified as Improper Authentication (CWE-287) exists within the OAuth implementation of phpBB. The flaw is rooted in insufficient validation during the authentication process, which can be exploited to hijack user accounts. This issue is particularly severe because it affects default installations and remains exploitable even if OAuth functionality is disabled or unconfigured in the administrative settings. An unauthenticated remote attacker can exploit this over the network with low complexity and no user interaction to gain full unauthorized access to accounts.
Affected products
- phpBB phpBB
Timeline
- 2026-06-12: disclosed: CVE published to NVD via HackerOne report