{"answers":{"affected":"2 open source packages ship an affected version, including concrete5/concrete5. It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-8204 in the wild and no public exploit code.","fix":"Upgrade concrete5/concrete5 to 9.5.1 or later.","what":"CVE-2026-8204 is a medium-severity missing authorization vulnerability in Concretecms Concrete Cms, published on 21 May 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-2026-8204 and fix it if it is affected.\n\nWhat it is: CVE-2026-8204 is a medium-severity missing authorization vulnerability in Concretecms Concrete Cms, published on 21 May 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-2026-8204 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- concrete5/concrete5 (Packagist): affected all versions; fixed in 9.5.1\n- concrete5/concrete5 (Packagist): affected all versions; fixed in 9.5.1\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-2026-8204/ (Markdown: https://insights.sbomify.com/CVE-2026-8204/index.md)","id":"CVE-2026-8204","markdown":"https://insights.sbomify.com/CVE-2026-8204/index.md","name":"CVE-2026-8204","record":{"aliases":["GHSA-x2fp-hj8c-mmxh"],"analysis":{"component_type":"web_application","fix_type":"upgrade","impacts":["data_read"],"network_reachable":"yes","non_default_config":false,"product_category":"Concrete CMS","requires_auth":"none","summary":"Attackers can bypass authorization in the Calendar Event Frontend Dialog to access private calendar data via a public calendar block.","user_interaction":"not_required","vuln_class":"missing_authorization"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"ConcreteCMS","cpe":[{"product":"concrete_cms","vendor":"concretecms"}],"cvss":{"score":6.3,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-639","name":"Authorization Bypass Through User-Controlled Key"}],"description":"Concrete CMS 9.5.0 and below is vulnerable to authorization Bypass in the Calendar Event Frontend Dialog which can allow cross-calendar data disclosure. A public calendar block can be used as a pivot point to access private calendar data. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 6.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks Winston Crooker for reporting.","ecosystems":["Packagist"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"Concrete CMS 9.5.0 and below is vulnerable to Authorization Bypass in the Calendar Event Frontend Dialog","id":"CVE-2026-8204","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Packagist","product":"concretecms:concrete_cms","products":["concretecms:concrete_cms"],"type":"missing_authorization","year":"2026"},"n_packages":2,"n_references":1,"next":{"headline":"Concrete CMS is vulnerable to authorization bypass in the Calendar Block","id":"CVE-2026-8205"},"packages":[{"ecosystem":"Packagist","fixed":["9.5.1"],"introduced":["0"],"last_affected":[],"package":"concrete5/concrete5","purl":null,"source":"GHSA-x2fp-hj8c-mmxh"},{"ecosystem":"Packagist","fixed":["9.5.1"],"introduced":["0"],"last_affected":[],"package":"concrete5/concrete5","purl":"pkg:composer/concrete5/concrete5","source":"GHSA-x2fp-hj8c-mmxh"}],"prev":{"headline":"Concrete CMS 9.5.0 and below has Stored XSS on the height parameter","id":"CVE-2026-8203"},"products":["Concrete CMS"],"published":"2026-05-21","related":[{"cvss_score":9.8,"headline":"Concrete CMS allows unauthorized access because directories can be created with insecure permissions","id":"CVE-2023-48648","kev_date_added":null,"published":"2023-11-17"},{"cvss_score":9.8,"headline":"Code injection in concrete CMS","id":"CVE-2022-21829","kev_date_added":null,"published":"2022-06-24"},{"cvss_score":9.8,"headline":"Server-Side Request Forgery vulnerability in concrete5","id":"CVE-2021-22958","kev_date_added":null,"published":"2021-10-07"},{"cvss_score":9.8,"headline":"Path traversal in n/a","id":"CVE-2021-40098","kev_date_added":null,"published":"2021-09-27"},{"cvss_score":9.4,"headline":"Concrete CMS Vulnerable to Relative Path Traversal","id":"CVE-2026-8134","kev_date_added":null,"published":"2026-05-21"},{"cvss_score":9.1,"headline":"Path traversal in Concrete CMS","id":"CVE-2022-30117","kev_date_added":null,"published":"2022-06-24"},{"cvss_score":9.1,"headline":"Deserialization in n/a","id":"CVE-2021-40102","kev_date_added":null,"published":"2021-09-24"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-05-22","vendors":["Concrete CMS"]},"summary":"Attackers can bypass authorization in the Calendar Event Frontend Dialog to access private calendar data via a public calendar block.","url":"https://insights.sbomify.com/CVE-2026-8204/"}