{"id":"CVE-2026-104615","kind":"vulnerability","aliases":["CVE-2026-104615"],"related":[],"title":"Rancher Fleet: cluster registration accepts identity not bound to its token","description":"A security vulnerability was discovered in SUSE Rancher Fleet's cluster registration flow, in Fleet versions before 0.12, 0.13.0 up to 0.13.17, 0.14.0 up to 0.14.12, 0.15.0 up t o 0.15.17 and 0.16.0 up to 0.16.3. The cluster identity claimed by a registration request was accepted without being bound to the registration token that the request was made with. As a result, a registration request could be associated with a managed cluster that was originally registered with a different registration token.","summary":"Fleet, the Rancher tool that manages groups of Kubernetes clusters, accepted a cluster identity in a registration request without checking it against the registration token used. An attacker can associate a registration with a managed cluster that was originally registered with a different token.","severity":"high","cvss":7.9,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["fleet","infrastructure","kubernetes","rancher","self-hosted"],"not_affected_if":["fleet-not-used","version-outside-range"],"how_to_check":"- Check the Fleet version deployed in the management cluster, for example with `kubectl get deployment -n cattle-fleet-system fleet-controller -o jsonpath='{.spec.template.spec.containers[0].image}'`\n- Compare the version against the affected ranges: before `0.12`, `0.13.0` to `0.13.17`, `0.14.0` to `0.14.12`, `0.15.0` to `0.15.17`, `0.16.0` to `0.16.3`","fix":"- Fleet: move to a version outside the affected ranges (the sources list the ranges above but do not name the fixed release for each line)","status":"open","published_at":"2026-10-30T16:17:36+00:00","first_seen_at":"2026-10-30T16:31:25+00:00","triaged_at":"2026-10-30T16:31:59+00:00","updated_at":"2026-10-30T16:31:59+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-30T16:31:59Z","model":"claude-haiku-5-5","output":{"fix":"- Fleet: move to a version outside the affected ranges (the sources list the ranges above but do not name the fixed release for each line)","reach":"unknown","title":"Rancher Fleet: cluster registration accepts identity not bound to its token","impact":"medium","summary":"Fleet, the Rancher tool that manages groups of Kubernetes clusters, accepted a cluster identity in a registration request without checking it against the registration token used. An attacker can associate a registration with a managed cluster that was originally registered with a different token.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["rancher","fleet","kubernetes","self-hosted"],"confidence":0.6,"fix_status":"unknown","needs_auth":"unknown","worst_case":"a registration is tied to another cluster's managed identity","analyst_note":"Find the fixed Fleet release for each affected line and confirm whether an attacker needs a valid registration token; see the NVD entry linked in the sources.","how_to_check":"- Check the Fleet version deployed in the management cluster, for example with `kubectl get deployment -n cattle-fleet-system fleet-controller -o jsonpath='{.spec.template.spec.containers[0].image}'`\n- Compare the version against the affected ranges: before `0.12`, `0.13.0` to `0.13.17`, `0.14.0` to `0.14.12`, `0.15.0` to `0.15.17`, `0.16.0` to `0.16.3`","plain_action":"","needs_analyst":true,"not_affected_if":["fleet-not-used","version-outside-range"],"who_is_affected":"Teams that run Rancher Fleet to register and manage downstream Kubernetes clusters are exposed when their Fleet version falls in an affected range. The flaw sits in the cluster registration path, so the exposure depends on whether that path is reachable by untrusted callers in the deployment. Teams not using Fleet, or running a version outside the listed ranges, can skip it.","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000781,"input_tokens":4207,"output_tokens":720,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-104615':14A,17A '-2026':13A,16A '0.12':86C '0.13.0':87C '0.13.17':90C '0.14.0':91C '0.14.12':94C '0.15.0':95C '0.15.17':99C '0.16.0':101C '0.16.3':104C 'accept':5A,35B,114C 'associ':54B,136C 'attack':52B 'bound':8A,117C 'check':44B 'claim':108C 'cluster':3A,34B,37B,60B,79C,106C,140C 'could':134C 'cve':12A,15A 'differ':67B,147C 'discov':73C 'fleet':2A,18B,25B,77C,83C 'flow':81C 'group':31B 'host':24B 'ident':6A,38B,107C 'infrastructur':19B 'kubernet':20B,33B 'made':126C 'manag':30B,59B,139C 'o':98C 'origin':63B,143C 'rancher':1A,21B,27B,76C 'regist':64B,144C 'registr':4A,41B,48B,56B,80C,111C,120C,132C,148C 'request':42B,112C,124C,133C 'result':130C 'secur':70C 'self':23B 'self-host':22B 'suse':75C 'token':11A,49B,68B,121C,149C 'tool':28B 'use':50B 'version':84C 'vulner':71C 'without':43B,115C","nicknames":[],"mitigations":[],"who_affected":"Teams that run Rancher Fleet to register and manage downstream Kubernetes clusters are exposed when their Fleet version falls in an affected range. The flaw sits in the cluster registration path, so the exposure depends on whether that path is reachable by untrusted callers in the deployment. Teams not using Fleet, or running a version outside the listed ranges, can skip it.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"unknown","audience":"businesses","plain_action":null,"first_public_at":"2026-10-30T16:17:36+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:H","cvss_by":"meissner@suse.de","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-104615","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-104615","severity":null,"published_at":"2026-10-30T16:17:36+00:00","modified_at":"2026-10-30T16:17:36+00:00","first_seen_at":"2026-10-30T16:31:25+00:00","fetched_at":"2026-10-30T16:31:25+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}