{"cve":{"cve_id":"CVE-2026-10634","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":0.00162,"epss_percentile":0.05751,"epss_as_of":"2026-06-23","description":"Zephyr's native TCP stack iterates the global connection list in net_tcp_foreach() (subsys/net/ip/tcp.c) using the SYS_SLIST_FOR_EACH_CONTAINER_SAFE macro, which caches a pointer to the next list node. Prior to this fix the function released tcp_lock while invoking the per-connection callback and re-acquired it afterwards. During that window a concurrent tcp_conn_release(), running on the dedicated TCP work-queue thread when a connection's reference count drops to zero (e.g. a remote peer closing or resetting the connection), can remove and k_mem_slab_free() the cached next connection. When the iterator advances it dereferences the freed (and possibly reallocated) slab memory — a use-after-free that can crash the system (denial of service) and, if the slot has been reused, cause the callback to operate on an attacker-influenced object (potential information disclosure or further fault). net_tcp_foreach() is reached in production via the 'net conn' network shell command and via net_tcp_close_all_for_iface() on interface-down; the freeing side is driven by ordinary TCP traffic. The fix moves the connection/context teardown in tcp_conn_release() inside the tcp_lock critical section and keeps tcp_lock held across the callback in net_tcp_foreach(). The defect was introduced with the modern (TCP2) stack in 2020 and affects releases up to and including v4.4.0.","published_at":"2026-06-15T14:16:43.871000Z","last_modified_at":null,"cvss_v3_score":4.8,"cvss_v3_vector":"CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","cvss_v3_severity":"MEDIUM","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":["CWE-416"],"nvd_references":["https://github.com/zephyrproject-rtos/zephyr/commit/cd85e0e890ab89815c4cbc0a8fbc03a3efa84dc2","https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-6c57-xfhw-j26x"],"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":"2026-06-28T23:28:51.044453Z"},"effective_severity":"MEDIUM","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"A","value_label":"Adjacent"},{"metric":"AC","name":"Attack Complexity","value":"H","value_label":"High"},{"metric":"PR","name":"Privileges Required","value":"L","value_label":"Low"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"U","value_label":"Unchanged"},{"metric":"C","name":"Confidentiality","value":"N","value_label":"None"},{"metric":"I","name":"Integrity","value":"N","value_label":"None"},{"metric":"A","name":"Availability","value":"H","value_label":"High"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"zephyrproject","vendor_name":"zephyrproject","product_slug":"zephyr","product_name":"zephyr","version_start":"2.5.0","version_start_inclusive":true,"version_end":"4.5.0","version_end_inclusive":false,"cpe23_uri":"cve5:zephyrproject:zephyr:2.5.0:4.5.0"}],"exploit_refs":[],"news":[],"references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/cd85e0e890ab89815c4cbc0a8fbc03a3efa84dc2","source_type":"PATCH","tags":["patch"]},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-6c57-xfhw-j26x","source_type":"VENDOR_ADVISORY","tags":["advisory"]}],"timeline":[{"type":"published","at":"2026-06-15T14:16:43.871000Z","label":"CVE published","source":null},{"type":"cvss_changed","at":"2026-06-28T17:50:30.876171Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:50:30.876171Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:50:30.876171Z","label":"CVSS score revised","source":"cvelistv5"}]}