CVE•Published 2026-09-11•Modified 2026-09-11•0 articles on news•5 live references•NVD data

CVE-2026-81906

Vulnerability data via NVD (ingested)

CVSS v3.1

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EPSS percentile

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Weaknesses (CWE)

CWE-288Authentication Bypass Using an Alternate Path or Channel

Description

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.

Timeline

Published 2026-09-11

Modified 2026-09-11

External references

NVD MITRE Exploit-DB GitHub PoC VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2026-81906

Hosts Shodan has explicitly fingerprinted as vulnerable.

More intel sources (5)

Shodan report

vuln:CVE-2026-81906

Country / ASN / product breakdown for the vuln query.

Censys

vulnerabilities.cve_id: CVE-2026-81906

Censys host search filtered to this CVE id.

grep.app

CVE-2026-81906