{"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"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-42209", "role": "CISA Coordinator", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-05-11T15:59:23.887272Z"}}}], "references": [{"url": "https://github.com/halfgaar/FlashMQ/issues/167", "tags": ["exploit"]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-05-11T15:59:17.095Z"}}], "cna": {"title": "FlashMQ: Division by zero crash when using non-default deferred retained message setting", "source": {"advisory": "GHSA-2789-vfcg-5922", "discovery": "UNKNOWN"}, "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 6.5, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}}], "affected": [{"vendor": "halfgaar", "product": "FlashMQ", "versions": [{"status": "affected", "version": "< 1.26.1"}]}], "references": [{"url": "https://github.com/halfgaar/FlashMQ/security/advisories/GHSA-2789-vfcg-5922", "name": "https://github.com/halfgaar/FlashMQ/security/advisories/GHSA-2789-vfcg-5922", "tags": ["x_refsource_CONFIRM"]}, {"url": "https://github.com/halfgaar/FlashMQ/issues/167", "name": "https://github.com/halfgaar/FlashMQ/issues/167", "tags": ["x_refsource_MISC"]}, {"url": "https://github.com/halfgaar/FlashMQ/commit/193b6e7767889511cfa8e933908ea5e6a1077a1f", "name": "https://github.com/halfgaar/FlashMQ/commit/193b6e7767889511cfa8e933908ea5e6a1077a1f", "tags": ["x_refsource_MISC"]}, {"url": "https://github.com/halfgaar/FlashMQ/releases/tag/v1.26.1", "name": "https://github.com/halfgaar/FlashMQ/releases/tag/v1.26.1", "tags": ["x_refsource_MISC"]}], "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."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-369", "description": "CWE-369: Divide By Zero"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-05-08T21:40:43.284Z"}}}, "cveMetadata": {"cveId": "CVE-2026-42209", "state": "PUBLISHED", "dateUpdated": "2026-05-11T15:59:27.626Z", "dateReserved": "2026-04-25T05:04:37.028Z", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "datePublished": "2026-05-08T21:40:43.284Z", "assignerShortName": "GitHub_M"}, "dataVersion": "5.2"}

{"cveTags": [], "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."}], "id": "CVE-2026-42209", "lastModified": "2026-05-13T16:52:48.773", "metrics": {"cvssMetricV31": [{"cvssData": {"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"}, "exploitabilityScore": 2.8, "impactScore": 3.6, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-05-08T22:16:32.103", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/halfgaar/FlashMQ/commit/193b6e7767889511cfa8e933908ea5e6a1077a1f"}, {"source": "security-advisories@github.com", "url": "https://github.com/halfgaar/FlashMQ/issues/167"}, {"source": "security-advisories@github.com", "url": "https://github.com/halfgaar/FlashMQ/releases/tag/v1.26.1"}, {"source": "security-advisories@github.com", "url": "https://github.com/halfgaar/FlashMQ/security/advisories/GHSA-2789-vfcg-5922"}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "url": "https://github.com/halfgaar/FlashMQ/issues/167"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-369"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,1.26.1)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "cna", "scores": [{"score": 100.0, "source": "cna"}]}, "original": {"product": "FlashMQ", "source": "cna", "vendor": "halfgaar"}, "product": "flashmq", "vendor": "halfgaar"}], "created": "2026-05-08T23:30:15.347690+00:00", "updated": "2026-05-10T21:24:47.189541+00:00", "vendors": ["halfgaar", "halfgaar$PRODUCT$flashmq"]}