{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-42209","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-04-25T05:04:37.028Z","datePublished":"2026-05-08T21:40:43.284Z","dateUpdated":"2026-05-11T15:59:27.626Z"},"containers":{"cna":{"title":"FlashMQ: Division by zero crash when using non-default deferred retained message setting","problemTypes":[{"descriptions":[{"cweId":"CWE-369","lang":"en","description":"CWE-369: Divide By Zero","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"references":[{"name":"https://github.com/halfgaar/FlashMQ/security/advisories/GHSA-2789-vfcg-5922","tags":["x_refsource_CONFIRM"],"url":"https://github.com/halfgaar/FlashMQ/security/advisories/GHSA-2789-vfcg-5922"},{"name":"https://github.com/halfgaar/FlashMQ/issues/167","tags":["x_refsource_MISC"],"url":"https://github.com/halfgaar/FlashMQ/issues/167"},{"name":"https://github.com/halfgaar/FlashMQ/commit/193b6e7767889511cfa8e933908ea5e6a1077a1f","tags":["x_refsource_MISC"],"url":"https://github.com/halfgaar/FlashMQ/commit/193b6e7767889511cfa8e933908ea5e6a1077a1f"},{"name":"https://github.com/halfgaar/FlashMQ/releases/tag/v1.26.1","tags":["x_refsource_MISC"],"url":"https://github.com/halfgaar/FlashMQ/releases/tag/v1.26.1"}],"affected":[{"vendor":"halfgaar","product":"FlashMQ","versions":[{"version":"< 1.26.1","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-05-08T21:40:43.284Z"},"descriptions":[{"lang":"en","value":"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."}],"source":{"advisory":"GHSA-2789-vfcg-5922","discovery":"UNKNOWN"}},"adp":[{"references":[{"url":"https://github.com/halfgaar/FlashMQ/issues/167","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-11T15:59:23.887272Z","id":"CVE-2026-42209","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-05-11T15:59:27.626Z"}}]}}