{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-81903 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-81903 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-81903 is a high-severity cross-site scripting vulnerability in Concretecms Concrete Cms, published on 14 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-81903 and fix it if it is affected.\n\nWhat it is: CVE-2026-81903 is a high-severity cross-site scripting vulnerability in Concretecms Concrete Cms, published on 14 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2026-81903 in the wild and no public exploit code.\n\nAffected product: Concretecms 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-2026-81903/ (Markdown: https://insights.sbomify.com/CVE-2026-81903/index.md)","id":"CVE-2026-81903","markdown":"https://insights.sbomify.com/CVE-2026-81903/index.md","name":"CVE-2026-81903","record":{"aliases":["GHSA-6338-gx7c-fcjj"],"analysis":{"component_type":"web_application","fix_type":"upgrade","impacts":["account_takeover","privilege_escalation"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Concrete CMS","requires_auth":"high_privilege","summary":"Stored XSS in Concrete CMS allows attackers to execute scripts in admin sessions via unvalidated page container icons, leading to session theft.","user_interaction":"required","vuln_class":"xss"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"ConcreteCMS","cpe":[{"product":"concrete_cms","vendor":"concretecms"}],"cvss":{"score":7,"severity":"high","source":"cna","vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"}],"description":"Concrete CMS versions 9.0.0 to 9.5.2 stored the Page Container icon value submitted through the dashboard without validating it against the set of known container icons. The unvalidated value was later concatenated into the src attribute of an img tag by a helper that did not encode attribute output, and was rendered raw in the Containers dashboard list and editor views. A user with delegated access to the Page Containers dashboard could store a crafted icon value that broke out of the src attribute and executed script in the authenticated session of another editor or administrator who viewed the list, enabling session token theft and privileged dashboard actions. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.0 with vector CVSS:4.0/AV:A/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Andrew Gonzalez 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":"Concrete CMS 9.0.0 to 9.5.2 is vulnerable to Stored XSS via Page Container icon","id":"CVE-2026-81903","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"concretecms:concrete_cms","products":["concretecms:concrete_cms"],"type":"xss","year":"2026"},"n_packages":0,"n_references":1,"next":{"headline":"Concrete CMS before 9.5.3 is vulnerable to Missing Authorization in Stack/Container Sub-Block Asset Registration","id":"CVE-2026-81904"},"packages":[],"prev":{"headline":"Concrete CMS 9.0.0 to 9.5.2 is vulnerable to CSRF on Orphan Block Cleanup","id":"CVE-2026-81902"},"products":["Concrete CMS"],"published":"2026-09-14","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":"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":"2026-09-15","vendors":["Concrete CMS"]},"summary":"Stored XSS in Concrete CMS allows attackers to execute scripts in admin sessions via unvalidated page container icons, leading to session theft.","url":"https://insights.sbomify.com/CVE-2026-81903/"}