{"id":"CVE-2026-111855","kind":"vulnerability","aliases":["CVE-2026-111855"],"related":[],"title":"Tektronix 3 Series MDO: path traversal in web interface reads arbitrary files","description":"An issue was discovered on Tektronix 3 Series MDO devices before 1.21.1. A path traversal vulnerability exists in the web management interface of the device. Insufficient validation of user-supplied file paths allows remote attackers to read arbitrary files accessible to the application. Depending on configuration, exploitation may be possible without authentication.","summary":"Tektronix 3 Series MDO oscilloscopes before firmware 1.21.1 have a path traversal flaw in their web management interface. A remote attacker can read arbitrary files the application can access, and depending on configuration this may not require logging in.","severity":"high","cvss":7.5,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["infrastructure","mdo","tektronix","test-equipment","web-management-interface"],"not_affected_if":["firmware-1.21.1-or-later","no-network-exposure"],"how_to_check":"- Check the installed firmware version on the device (the sources do not say where in the interface; unknown)\n- Check whether the web management interface is reachable from untrusted networks (unknown)","fix":"- Update Tektronix 3 Series MDO firmware to `1.21.1` or later\n- Restrict access to the web management interface to trusted management networks until updated","status":"open","published_at":"2026-10-17T02:17:18+00:00","first_seen_at":"2026-10-23T21:57:14+00:00","triaged_at":"2026-10-25T03:24:47+00:00","updated_at":"2026-10-25T03:24:47+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-25T03:24:47Z","model":"claude-haiku-5-5","output":{"fix":"- Update Tektronix 3 Series MDO firmware to `1.21.1` or later\n- Restrict access to the web management interface to trusted management networks until updated","reach":"network","title":"Tektronix 3 Series MDO: path traversal in web interface reads arbitrary files","impact":"medium","summary":"Tektronix 3 Series MDO oscilloscopes before firmware 1.21.1 have a path traversal flaw in their web management interface. A remote attacker can read arbitrary files the application can access, and depending on configuration this may not require logging in.","category":"infrastructure","nicknames":[],"who_cares":["tektronix","mdo","test-equipment","web-management-interface"],"confidence":0.6,"needs_auth":"unknown","worst_case":"Remote attacker reads arbitrary files the device application can access","analyst_note":"Confirm from the Tektronix advisory whether authentication is required by default and which files are readable; the NVD entry alone does not say.","how_to_check":"- Check the installed firmware version on the device (the sources do not say where in the interface; unknown)\n- Check whether the web management interface is reachable from untrusted networks (unknown)","needs_analyst":true,"not_affected_if":["firmware-1.21.1-or-later","no-network-exposure"],"who_is_affected":"Teams that run Tektronix 3 Series MDO devices with the web management interface enabled. Exposure is greater if the interface is reachable from the internet or untrusted networks, and if authentication is not required by configuration. Devices kept off the network or running firmware 1.21.1 or later are not affected.","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000625,"input_tokens":3321,"output_tokens":586,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-111855':15A,18A '-2026':14A,17A '1.21.1':36B,78C '3':2A,30B,73C 'access':57B,107C 'allow':100C 'applic':55B,110C 'arbitrari':11A,52B,105C 'attack':49B,102C 'authent':119C 'configur':61B,113C 'cve':13A,16A 'depend':59B,111C 'devic':76C,91C 'discov':70C 'equip':24B 'exist':83C 'exploit':114C 'file':12A,53B,98C,106C 'firmwar':35B 'flaw':41B 'infrastructur':19B 'insuffici':92C 'interfac':9A,28B,46B,88C 'issu':68C 'log':66B 'manag':27B,45B,87C 'may':63B,115C 'mdo':4A,20B,32B,75C 'oscilloscop':33B 'path':5A,39B,80C,99C 'possibl':117C 'read':10A,51B,104C 'remot':48B,101C 'requir':65B 'seri':3A,31B,74C 'suppli':97C 'tektronix':1A,21B,29B,72C 'test':23B 'test-equip':22B 'travers':6A,40B,81C 'user':96C 'user-suppli':95C 'valid':93C 'vulner':82C 'web':8A,26B,44B,86C 'web-management-interfac':25B 'without':118C","nicknames":[],"mitigations":[],"who_affected":"Teams that run Tektronix 3 Series MDO devices with the web management interface enabled. Exposure is greater if the interface is reachable from the internet or untrusted networks, and if authentication is not required by configuration. Devices kept off the network or running firmware 1.21.1 or later are not affected.","tier":"B","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-17T02:17:18+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","cvss_by":"cve@mitre.org","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-111855","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-111855","severity":null,"published_at":"2026-10-17T02:17:18+00:00","modified_at":"2026-10-21T22:16:47+00:00","first_seen_at":"2026-10-23T21:57:14+00:00","fetched_at":"2026-10-23T22:28:55+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"}