{"answers":{"affected":"","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42209 exists.","fix":"No fix has been published for CVE-2026-42209 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-42209 is a medium-severity denial of service vulnerability in halfgaar FlashMQ, published on 8 May 2026. Any signed-in user can exploit it over the network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-42209 and fix it if it is affected.\n\nWhat it is: CVE-2026-42209 is a medium-severity denial of service vulnerability in halfgaar FlashMQ, published on 8 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42209 exists.\n\nAffected product: halfgaar FlashMQ. 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-2026-42209/ (Markdown: https://insights.sbomify.com/CVE-2026-42209/index.md)","id":"CVE-2026-42209","markdown":"https://insights.sbomify.com/CVE-2026-42209/index.md","name":"CVE-2026-42209","record":{"aliases":["GHSA-2789-vfcg-5922"],"analysis":{"component_type":"server_software","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":true,"product_category":"MQTT broker","requires_auth":"low_privilege","summary":"Remote attackers can crash the FlashMQ MQTT broker via division by zero if specific non-default retained message settings are enabled.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[],"cvss":{"score":6.5,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-369","name":"Divide By Zero"}],"description":"FlashMQ is a MQTT broker/server, designed for multi-CPU environments. Prior to version 1.26.1, a remote client with retained publish permission can crash the FlashMQ broker when both set_retained_message_defer_timeout and set_retained_message_defer_timeout_spread are configured to non-default values, resulting in denial of service. If anonymous retained publishing is allowed, no authentication is required; otherwise, the attacker needs the corresponding publish permission. This issue has been patched in version 1.26.1.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":false,"headline":"FlashMQ: Division by zero crash when using non-default deferred retained message setting","id":"CVE-2026-42209","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":0,"n_references":4,"next":{"headline":"Webmin 2FA requirement bypass","id":"CVE-2026-42210"},"packages":[],"prev":{"headline":"BerriAI LiteLLM SQL Injection","id":"CVE-2026-42208"},"products":["FlashMQ"],"published":"2026-05-08","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":"no","exploitation":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-05-11","vendors":["halfgaar"]},"summary":"Remote attackers can crash the FlashMQ MQTT broker via division by zero if specific non-default retained message settings are enabled.","url":"https://insights.sbomify.com/CVE-2026-42209/"}