{"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-2026-8428 in the wild and no public exploit code.","fix":"Upgrade concrete5/concrete5 to 9.5.1 or later.","what":"CVE-2026-8428 is a high-severity vulnerability in Concretecms Concrete Cms, published on 21 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-8428 and fix it if it is affected.\n\nWhat it is: CVE-2026-8428 is a high-severity vulnerability in Concretecms Concrete Cms, published on 21 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2026-8428 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-2026-8428/ (Markdown: https://insights.sbomify.com/CVE-2026-8428/index.md)","id":"CVE-2026-8428","markdown":"https://insights.sbomify.com/CVE-2026-8428/index.md","name":"CVE-2026-8428","record":{"aliases":["GHSA-prxr-vjgc-2cq9"],"analysis":{"component_type":"web_application","fix_type":"patch","impacts":["code_execution","data_modify"],"network_reachable":"yes","non_default_config":true,"product_category":"Concrete CMS","requires_auth":"none","summary":"Attackers can force CMS updates to malicious versions via CSRF if update conditions are met, leading to code execution.","user_interaction":"required","vuln_class":"csrf"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"ConcreteCMS","cpe":[{"product":"concrete_cms","vendor":"concretecms"}],"cvss":{"score":7.5,"severity":"high","source":"cna","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-829","name":"Inclusion of Functionality from Untrusted Control Sphere"},{"id":"CWE-352","name":"Cross-Site Request Forgery"}],"description":"Concrete CMS 9.5.0 and below emits a CSRF token in the local_available_update.php view ($token-\u003eoutput('do_update')) but the corresponding do_update() method in concrete/controllers/single_page/dashboard/system/update/update.php never calls $this-\u003etoken-\u003evalidate('do_update'). The form is rendered as a POST form, meaning the token reaches the browser, but because the controller discards it without verification, an attacker can craft a cross-site POST that triggers a core CMS update to an attacker-specified version string.  In order to be vulnerable, theictim must be passing canUpgrade()anda valid update version must be present under DIR_CORE_UPDATES. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 7.5 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks https://github.com/maru1009 for reporting.","ecosystems":["Packagist"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"CSRF token is not validated in the core CMS update controller for Concrete CMS 9.5.0 and below","id":"CVE-2026-8428","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Packagist","product":"concretecms:concrete_cms","products":["concretecms:concrete_cms"],"type":"csrf","year":"2026"},"n_packages":2,"n_references":1,"next":{"headline":"SPIP \u003c 4.4.14 Remote Code Execution via Private Space","id":"CVE-2026-8429"},"packages":[{"ecosystem":"Packagist","fixed":["9.5.1"],"introduced":["0"],"last_affected":[],"package":"concrete5/concrete5","purl":null,"source":"GHSA-prxr-vjgc-2cq9"},{"ecosystem":"Packagist","fixed":["9.5.1"],"introduced":["0"],"last_affected":[],"package":"concrete5/concrete5","purl":"pkg:composer/concrete5/concrete5","source":"GHSA-prxr-vjgc-2cq9"}],"prev":{"headline":"Concrete CMS is vulnerable to Cross Site Request Forgery (CSRF) at concrete/controllers/backend/file removeFavoriteFolder($id)","id":"CVE-2026-8427"},"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":"total"},"state":"PUBLISHED","updated":"2026-05-22","vendors":["Concrete CMS"]},"summary":"Attackers can force CMS updates to malicious versions via CSRF if update conditions are met, leading to code execution.","url":"https://insights.sbomify.com/CVE-2026-8428/"}