{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-81906 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-81906 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-81906 is a medium-severity authentication bypass vulnerability in Concrete CMS, published on 10 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-81906 and fix it if it is affected.\n\nWhat it is: CVE-2026-81906 is a medium-severity authentication bypass vulnerability in Concrete CMS, published on 10 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-81906 in the wild and no public exploit code.\n\nAffected product: Concrete CMS. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-81906/ (Markdown: https://insights.sbomify.com/CVE-2026-81906/index.md)","id":"CVE-2026-81906","markdown":"https://insights.sbomify.com/CVE-2026-81906/index.md","name":"CVE-2026-81906","record":{"aliases":["GHSA-2c5v-fhhf-mwq5"],"analysis":{"component_type":"web_application","fix_type":"upgrade","impacts":["security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"Concrete CMS","requires_auth":"none","summary":"Attackers can bypass deactivated or unvalidated account checks during OAuth login to establish authenticated sessions in Concrete CMS.","user_interaction":"not_required","vuln_class":"auth_bypass"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"ConcreteCMS","cpe":[],"cvss":{"score":6.3,"severity":"medium","source":"cna","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","version":"4.0"},"cwes":[{"id":"CWE-288","name":"Authentication 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.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":false,"headline":"[UNREVIEWED] OAuth Callback Login Bypasses Deactivated-Account Checks","id":"CVE-2026-81906","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"auth_bypass","year":"2026"},"n_packages":0,"n_references":1,"next":{"headline":"Cross-site request forgery in Concrete CMS","id":"CVE-2026-81907"},"packages":[],"prev":{"headline":"Business logic in Concrete CMS","id":"CVE-2026-81905"},"products":["Concrete CMS"],"published":"2026-09-10","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-09-11","vendors":["Concrete CMS"]},"summary":"Attackers can bypass deactivated or unvalidated account checks during OAuth login to establish authenticated sessions in Concrete CMS.","url":"https://insights.sbomify.com/CVE-2026-81906/"}