CVE-2026-81906[UNREVIEWED] OAuth Callback Login Bypasses Deactivated-Account Checks
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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Concrete CMS OAuth callback login path prior to version 9.5.3 did not check whether an account was active or email-validated before establishing a session. A deactivated or unvalidated user with an existing OAuth binding could complete authentication and receive a session that was fully authenticated for the callback response, with the login recorded and login events dispatched. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 6.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.
- CVSS
- 6.3 MEDIUM (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
- Weakness (CWE)
- CWE-288
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- ConcreteCMS
- NVD analysis
- Deferred
- Record last updated
- Sep 11, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Concrete CMS Concrete CMS concrete_cms:concrete_cms (from the name) | from 5.0.0 through 9.5.2 | CNA record |
References
- https://documentation.concretecms.org/developers/introduction/version-history/953-release-notesrelease-notes
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.