{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-15576 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-15576 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-15576 is a medium-severity authentication bypass vulnerability in Checkmk, published on 21 Aug 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-2026-15576 and fix it if it is affected.\n\nWhat it is: CVE-2026-15576 is a medium-severity authentication bypass vulnerability in Checkmk, published on 21 Aug 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-2026-15576 in the wild and no public exploit code.\n\nAffected product: 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-2026-15576/ (Markdown: https://insights.sbomify.com/CVE-2026-15576/index.md)","id":"CVE-2026-15576","markdown":"https://insights.sbomify.com/CVE-2026-15576/index.md","name":"CVE-2026-15576","record":{"aliases":["GHSA-8fww-64wc-46pf","UBUNTU-CVE-2026-15576"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["security_bypass","data_modify"],"network_reachable":"yes","non_default_config":true,"product_category":"IT monitoring software","requires_auth":"none","summary":"Unauthenticated attackers can bypass mTLS verification on Checkmk relay endpoints by using a placeholder identity, affecting specific enterprise editions.","user_interaction":"not_required","vuln_class":"auth_bypass"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Checkmk","cpe":[],"cvss":{"score":6.9,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-306","name":"Missing Authentication for Critical Functionality"}],"description":"Improper authentication in the agent receiver of Checkmk \u003c2.5.0p10 allows an unauthenticated remote attacker to bypass mutual TLS client certificate verification of relay endpoints by supplying a fixed placeholder identity in the request URL, resulting in limited impact on integrity and availability. Only the Cloud, Ultimate and Ultimate MT editions are affected, as other editions do not expose relay endpoints.","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":"Agent receiver accepts mTLS requests without a client certificate","id":"CVE-2026-15576","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":"Git Sync connection configuration can be modified with read-only access","id":"CVE-2026-15577"},"packages":[],"prev":{"headline":"Sensitive Information Disclosure Due to Enabled Debug Mode in Production in SFM Software's Costifier","id":"CVE-2026-15575"},"products":["Checkmk"],"published":"2026-08-21","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":"2026-08-21","vendors":["Checkmk GmbH"]},"summary":"Unauthenticated attackers can bypass mTLS verification on Checkmk relay endpoints by using a placeholder identity, affecting specific enterprise editions.","url":"https://insights.sbomify.com/CVE-2026-15576/"}