{"id":"CVE-2026-121370","kind":"vulnerability","aliases":["CVE-2026-121370"],"related":[],"title":"Arista EOS: unauthenticated PTP traffic can cause denial of service","description":"On affected platforms running Arista EOS with Precision Time Protocol (PTP) configured, an unauthenticated attacker with network access to a PTP-enabled port can create a denial of service (DoS) condition by sending traffic to the system.","summary":"Arista EOS switches running Precision Time Protocol (PTP) can be knocked over by an unauthenticated attacker who sends traffic to a PTP-enabled port. The result is a denial of service, not code execution or data access.","severity":"critical","cvss":9.2,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["arista-eos","infrastructure","network-switches","ptp"],"not_affected_if":["ptp-not-configured"],"how_to_check":"- Check whether PTP is configured on the switch (the sources do not name the exact command; unknown)\n- Check the EOS version in use with `show version` (affected ranges unknown from the sources)","fix":null,"status":"open","published_at":"2026-11-10T20:18:56+00:00","first_seen_at":"2026-11-10T20:46:04+00:00","triaged_at":"2026-11-10T20:47:20+00:00","updated_at":"2026-11-10T20:50:02+00:00","category":"infrastructure","confidence":0.4,"triage":{"at":"2026-11-10T20:47:20Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Arista EOS: unauthenticated PTP traffic can cause denial of service","impact":"low","summary":"Arista EOS switches running Precision Time Protocol (PTP) can be knocked over by an unauthenticated attacker who sends traffic to a PTP-enabled port. The result is a denial of service, not code execution or data access.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["arista-eos","ptp","network-switches"],"confidence":0.5,"fix_status":"unknown","needs_auth":"no","worst_case":"Switch becomes unavailable, causing denial of service on the network","analyst_note":"Find the affected EOS version ranges and fixed releases in the Arista security advisory for CVE-2026-121370; the NVD entry alone does not list them.","how_to_check":"- Check whether PTP is configured on the switch (the sources do not name the exact command; unknown)\n- Check the EOS version in use with `show version` (affected ranges unknown from the sources)","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["ptp-not-configured"],"who_is_affected":"Only switches running Arista EOS with Precision Time Protocol configured and a PTP-enabled port reachable by an attacker are exposed. Teams without PTP configured on Arista gear can likely skip it. Affected version ranges are not stated in the sources.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"yes","severity_if_unknown":"critical"},"cost_usd":0.000718,"input_tokens":4536,"output_tokens":528,"severity_before":"critical"},"analyst_status":"done","analyst_note":"Find the affected EOS version ranges and fixed releases in the Arista security advisory for CVE-2026-121370; the NVD entry alone does not list them.","search":"'-121370':13A,16A '-2026':12A,15A 'access':62B,80C 'affect':64C 'arista':1A,18B,25B,67C 'arista-eo':17B 'attack':40B,77C 'caus':7A 'code':58B 'condit':94C 'configur':74C 'creat':88C 'cve':11A,14A 'data':61B 'denial':8A,54B,90C 'dos':93C 'enabl':48B,85C 'eo':2A,19B,26B,68C 'execut':59B 'infrastructur':20B 'knock':35B 'network':22B,79C 'network-switch':21B 'platform':65C 'port':49B,86C 'precis':29B,70C 'protocol':31B,72C 'ptp':4A,24B,32B,47B,73C,84C 'ptp-enabl':46B,83C 'result':51B 'run':28B,66C 'send':42B,96C 'servic':10A,56B,92C 'switch':23B,27B 'system':100C 'time':30B,71C 'traffic':5A,43B,97C 'unauthent':3A,39B,76C","nicknames":[],"mitigations":[],"who_affected":"Only switches running Arista EOS with Precision Time Protocol configured and a PTP-enabled port reachable by an attacker are exposed. Teams without PTP configured on Arista gear can likely skip it. Affected version ranges are not stated in the sources.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"unknown","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["aristaeos","critical","infrastructure","networkswitches","ptp"],"campaign_type":null,"search_a":"'-121370':13A,16A '-2026':12A,15A 'arista':1A 'caus':7A 'cve':11A,14A 'denial':8A 'eo':2A 'ptp':4A 'servic':10A 'traffic':5A 'unauthent':3A","search_b":"'access':62B 'arista':18B,25B 'arista-eo':17B 'attack':40B 'code':58B 'data':61B 'denial':54B 'enabl':48B 'eo':19B,26B 'execut':59B 'infrastructur':20B 'knock':35B 'network':22B 'network-switch':21B 'port':49B 'precis':29B 'protocol':31B 'ptp':24B,32B,47B 'ptp-enabl':46B 'result':51B 'run':28B 'send':42B 'servic':56B 'switch':23B,27B 'time':30B 'traffic':43B 'unauthent':39B","search_c":"'access':80C 'affect':64C 'arista':67C 'attack':77C 'condit':94C 'configur':74C 'creat':88C 'denial':90C 'dos':93C 'enabl':85C 'eo':68C 'network':79C 'platform':65C 'port':86C 'precis':70C 'protocol':72C 'ptp':73C,84C 'ptp-enabl':83C 'run':66C 'send':96C 'servic':92C 'system':100C 'time':71C 'traffic':97C 'unauthent':76C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T20:18:56+00:00","kev":null,"cvss_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:H/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","cvss_by":"psirt@arista.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-121370","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121370","severity":null,"published_at":"2026-11-10T20:18:56+00:00","modified_at":"2026-11-10T20:18:56+00:00","first_seen_at":"2026-11-10T20:46:04+00:00","fetched_at":"2026-11-10T20:46:04+00:00","note":null},{"source":"analyst","external_id":"CVE-2026-121370:2710","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121370","severity":null,"published_at":"2026-11-10T20:50:02+00:00","modified_at":"2026-11-10T20:50:02+00:00","first_seen_at":"2026-11-10T20:50:02+00:00","fetched_at":"2026-11-10T20:50:02+00:00","note":"Arista's own advisory for CVE-2026-121370 (published about 30 min ago, part of the Nov 10 batch) is not indexed yet. The arista.com index page sits behind a client challenge and search returned nothing for this id. Only NVD is linked, and it has no version ranges. Nothing verified. Revisit when the advisory appears: it should give affected EOS trains, fixed releases, PTP check/mitigation. CVSS v4 9.2 from psirt@arista.com is the vendor's own score. Availability only (VA:H/SA:H). Severity unchanged. X not searched, and no discussion found.","cites":["https://nvd.nist.gov/vuln/detail/CVE-2026-121370"]}],"documents":[{"id":118294,"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121370","title":"NVD CVE-2026-121370","kind":"other","source":"analyst","publisher":null,"text":null,"published_at":null,"relation":"describes","confidence":null,"note":null}],"disclosures":[],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}