{"answers":{"affected":"It affects 2 products.","exploited":"There is no known exploitation of CVE-2021-40906 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2021-40906 is a medium-severity cross-site scripting vulnerability in Checkmk Checkmk, published on 25 Mar 2022. 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-2021-40906 and fix it if it is affected.\n\nWhat it is: CVE-2021-40906 is a medium-severity cross-site scripting vulnerability in Checkmk Checkmk, published on 25 Mar 2022. 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-2021-40906 in the wild and no public exploit code.\n\nAffected product: Checkmk Checkmk. 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-2021-40906/ (Markdown: https://insights.sbomify.com/CVE-2021-40906/index.md)","id":"CVE-2021-40906","markdown":"https://insights.sbomify.com/CVE-2021-40906/index.md","name":"CVE-2021-40906","record":{"aliases":["GHSA-jv73-q4rg-p7qh","UBUNTU-CVE-2021-40906"],"analysis":{"component_type":"web_application","fix_type":"upgrade","impacts":["account_takeover","code_execution"],"network_reachable":"yes","non_default_config":false,"product_category":"CheckMK monitoring software","requires_auth":"none","summary":"Reflected XSS in CheckMK Raw Edition allows attackers to execute scripts, steal session cookies, or open backdoors via unauthenticated web service parameters.","user_interaction":"required","vuln_class":"xss"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"mitre","cpe":[{"product":"checkmk","vendor":"checkmk"},{"product":"checkmk","vendor":"tribe29"}],"cvss":{"score":6.1,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","version":"3.1"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"}],"description":"CheckMK Raw Edition software (versions 1.5.0 to 1.6.0) does not sanitise the input of a web service parameter that is in an unauthenticated zone. This Reflected XSS allows an attacker to open a backdoor on the device with HTML content and interpreted by the browser (such as JavaScript or other client-side scripts) or to steal the session cookies of a user who has previously authenticated via a man in the middle. Successful exploitation requires access to the web service resource without authentication.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":"2021-10-12","github_poc":1,"max_poc_stars":1,"metasploit":0,"nuclei":0,"refs":[{"date":"2021-10-12T09:30:38Z","kind":"github_poc","ref":"https://github.com/Edgarloyola/CVE-2021-40906","stars":1,"title":null}],"tier":"poc_unverified"},"has_fix":true,"headline":"Cross-site scripting in n/a","id":"CVE-2021-40906","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"checkmk:checkmk","products":["checkmk:checkmk"],"type":"xss","year":"2021"},"n_packages":0,"n_references":1,"next":{"headline":"SQL injection in n/a","id":"CVE-2021-40907"},"packages":[],"prev":{"headline":"File upload in n/a","id":"CVE-2021-40905"},"products":["n/a"],"published":"2022-03-25","related":[{"cvss_score":9.3,"headline":"omd: Local privilege escalation when executing omd commands as root","id":"CVE-2025-39666","kev_date_added":null,"published":"2026-04-07"},{"cvss_score":9.2,"headline":"Fix 2FA bypass via RestAPI","id":"CVE-2024-8606","kev_date_added":null,"published":"2024-09-23"},{"cvss_score":9.1,"headline":"PHP code injection in watolib","id":"CVE-2022-46836","kev_date_added":null,"published":"2023-02-20"},{"cvss_score":8.8,"headline":"Privilege Escalation in Windows License plugin for Checkmk Windows Agent","id":"CVE-2025-32919","kev_date_added":null,"published":"2025-10-09"},{"cvss_score":8.8,"headline":"Privilege escalation in Windows agent","id":"CVE-2024-28827","kev_date_added":null,"published":"2024-07-10"},{"cvss_score":8.8,"headline":"1-Click compromize via CSRF","id":"CVE-2024-28828","kev_date_added":null,"published":"2024-07-10"},{"cvss_score":8.8,"headline":"Unrestricted upload and download paths in check_sftp","id":"CVE-2024-28826","kev_date_added":null,"published":"2024-05-29"}],"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)"},{"class":"open","licence":"CC0","name":"PoC-in-GitHub"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-07-09","vendors":["n/a"]},"summary":"Reflected XSS in CheckMK Raw Edition allows attackers to execute scripts, steal session cookies, or open backdoors via unauthenticated web service parameters.","url":"https://insights.sbomify.com/CVE-2021-40906/"}