{"cve":{"cve_id":"CVE-2026-54412","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":0.00407,"epss_percentile":0.32369,"epss_as_of":"2026-06-23","description":"LiamBindle MQTT-C through version 1.1.6 contains a heap-based out-of-bounds read and integer underflow in the mqtt_unpack_publish_response() function in src/mqtt.c that allows a remote unauthenticated attacker controlling an MQTT broker - or able to inject MQTT traffic into an unencrypted session - to crash a subscribed MQTT-C client and potentially disclose adjacent heap memory by sending a single crafted PUBLISH packet. The function validates only that the fixed-header remaining_length is at least 4, then reads the 16-bit topic_name_size field from the broker-controlled packet and advances the parse pointer by that value without verifying that topic_name_size plus the surrounding overhead fits within remaining_length; it subsequently computes application_message_size as remaining_length - topic_name_size - 2 (QoS 0) or - 4 (QoS greater than 0) in unsigned arithmetic, producing an integer underflow that is then passed to memmove(). A PUBLISH packet with topic_name_size = 0xFFFF and remaining_length = 7 advances the parse pointer 65535 bytes past the receive buffer (out-of-bounds read) and causes an application_message_size near 2^32, crashing the process when the resulting memmove() is executed.","published_at":"2026-06-14T17:26:36.740000Z","last_modified_at":null,"cvss_v3_score":8.2,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H","cvss_v3_severity":"HIGH","cvss_v4_score":7.8,"cvss_v4_vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/AU:Y/V:D","cvss_v4_severity":"HIGH","ssvc_decision":null,"ssvc_exploitation":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":["CWE-125","CWE-191"],"nvd_references":["https://github.com/LiamBindle/MQTT-C","https://github.com/LiamBindle/MQTT-C/blob/v1.1.6/src/mqtt.c#L1334","https://cwe.mitre.org/data/definitions/125.html","https://cwe.mitre.org/data/definitions/191.html"],"vuln_status":null,"trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-24T00:09:39.878444Z","updated_at":"2026-06-28T23:30:54.391983Z"},"effective_severity":"HIGH","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"PR","name":"Privileges Required","value":"N","value_label":"None"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"U","value_label":"Unchanged"},{"metric":"C","name":"Confidentiality","value":"L","value_label":"Low"},{"metric":"I","name":"Integrity","value":"N","value_label":"None"},{"metric":"A","name":"Availability","value":"H","value_label":"High"}]},"cvss_v4_decoded":{"version":"4.0","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"AT","name":"Attack Requirements","value":"N","value_label":"None"},{"metric":"PR","name":"Privileges Required","value":"N","value_label":"None"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"VC","name":"Confidentiality (Vulnerable System)","value":"L","value_label":"Low"},{"metric":"VI","name":"Integrity (Vulnerable System)","value":"N","value_label":"None"},{"metric":"VA","name":"Availability (Vulnerable System)","value":"H","value_label":"High"},{"metric":"SC","name":"Confidentiality (Subsequent System)","value":"N","value_label":"None"},{"metric":"SI","name":"Integrity (Subsequent System)","value":"N","value_label":"None"},{"metric":"SA","name":"Availability (Subsequent System)","value":"N","value_label":"None"},{"metric":"E","name":"E","value":"P","value_label":"Physical"},{"metric":"AU","name":"AU","value":"Y","value_label":"Y"},{"metric":"V","name":"V","value":"D","value_label":"D"}]},"affected":[{"vendor_slug":"liambindle","vendor_name":"LiamBindle","product_slug":"mqtt-c","product_name":"MQTT-C","version_start":"0","version_start_inclusive":true,"version_end":"1.1.6","version_end_inclusive":true,"cpe23_uri":"cve5:liambindle:mqtt-c:0:1.1.6"}],"exploit_refs":[],"news":[],"references":[{"url":"https://github.com/LiamBindle/MQTT-C","source_type":"MISC","tags":[]},{"url":"https://github.com/LiamBindle/MQTT-C/blob/v1.1.6/src/mqtt.c#L1334","source_type":"MISC","tags":[]},{"url":"https://cwe.mitre.org/data/definitions/125.html","source_type":"MISC","tags":[]},{"url":"https://cwe.mitre.org/data/definitions/191.html","source_type":"MISC","tags":[]}],"timeline":[{"type":"published","at":"2026-06-14T17:26:36.740000Z","label":"CVE published","source":null},{"type":"cvss_changed","at":"2026-06-28T17:55:37.240342Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:55:37.240342Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:55:37.240342Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:55:37.240342Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:55:37.240342Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:55:37.240342Z","label":"CVSS score revised","source":"cvelistv5"}]}