{"id":"CVE-2026-8686","aliases":["EUVD-2026-30581","GHSA-6qh9-r6jp-2wxc"],"status":"published","title":"DoS from MQTT v5.0 Deserialization Fault in core MQTT","description":"Missing bounds validation in the MQTT v5.0 property parser in coreMQTT before 5.0.1 allows an MQTT broker to cause a denial of service by sending a crafted packet.\n\n\n\nTo remediate this issue, users should upgrade to v5.0.1.","severity":{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00388,"percentile":0.3313,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-125"],"published":"2026-05-15T18:38:10Z","modified":"2026-10-28T02:30:30Z","products":[{"vendor":"freertos","product":"coremqtt"}],"references":[{"url":"https://github.com/FreeRTOS/coreMQTT/releases/tag/v5.0.1","tags":["patch","Release Notes","fix"]},{"url":"https://aws.amazon.com/security/security-bulletins/2026-032-aws/","tags":["vendor-advisory","Vendor Advisory","advisory"]},{"url":"https://github.com/FreeRTOS/coreMQTT/security/advisories/GHSA-6qh9-r6jp-2wxc","tags":["third-party-advisory","Vendor Advisory","advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/8xxx/CVE-2026-8686.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-8686","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-8686","title":"DoS from MQTT v5.0 Deserialization Fault in core MQTT","description":"Missing bounds validation in the MQTT v5.0 property parser in coreMQTT before 5.0.1 allows an MQTT broker to cause a denial of service by sending a crafted packet.\n\n\n\nTo remediate this issue, users should upgrade to v5.0.1.","status":"published","published":"2026-05-15T18:38:10.651Z","modified":"2026-05-15T20:22:58.148Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-125"],"updated_at":"2026-11-02T13:48:02.226896Z"}],"euvd":[{"id":"EUVD-2026-30581","description":"Missing bounds validation in the MQTT v5.0 property parser in coreMQTT before 5.0.1 allows an MQTT broker to cause a denial of service by sending a crafted packet.\n\n\n\nTo remediate this issue, users should upgrade to v5.0.1.","status":"published","published":"2026-05-15T18:38:10Z","modified":"2026-05-15T20:22:58Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T19:04:28.290329Z"}],"nvd":[{"id":"CVE-2026-8686","description":"Missing bounds validation in the MQTT v5.0 property parser in coreMQTT before 5.0.1 allows an MQTT broker to cause a denial of service by sending a crafted packet.\n\n\n\nTo remediate this issue, users should upgrade to v5.0.1.","status":"published","published":"2026-05-15T19:17:05.057Z","modified":"2026-10-25T23:10:00.167Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"},{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","level":"critical","assessor":"primary"}],"cwes":["CWE-125"],"updated_at":"2026-11-02T14:12:19.39893Z"}],"osv":[{"id":"CVE-2026-8686","title":"DoS from MQTT v5.0 Deserialization Fault in core MQTT","description":"Missing bounds validation in the MQTT v5.0 property parser in coreMQTT before 5.0.1 allows an MQTT broker to cause a denial of service by sending a crafted packet.\n\n\n\nTo remediate this issue, users should upgrade to v5.0.1.","status":"published","published":"2026-05-15T18:38:10.651Z","modified":"2026-10-28T02:30:30.067314655Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-125"],"updated_at":"2026-11-02T15:45:19.210277Z"}]}}