{"id":"CVE-2026-103400","kind":"vulnerability","aliases":["CVE-2026-103400"],"related":[],"title":"Juniper Session Smart Router: local user can unmount filesystems or crash ember","description":"An Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') vulnerability in the ember service in Juniper Networks Session Smart Router and Session Smart Conductor allows an attacker with local access to unmount arbitrary filesystems or cause a denial of service via the creation of specially named directories and a service restart.","summary":"The ember service in Juniper Session Smart Router and Session Smart Conductor fails to neutralize special characters in directory names it uses downstream. A local attacker who creates specially named directories and triggers a service restart can unmount arbitrary filesystems or cause a denial of service.","severity":"medium","cvss":5.5,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["infrastructure","juniper","network-appliance","session-smart-conductor","session-smart-router"],"not_affected_if":["no-local-access"],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-10-28T17:17:23+00:00","first_seen_at":"2026-10-28T17:34:08+00:00","triaged_at":"2026-10-28T17:34:39+00:00","updated_at":"2026-10-28T17:34:39+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-28T17:34:39Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"local","title":"Juniper Session Smart Router: local user can unmount filesystems or crash ember","impact":"medium","summary":"The ember service in Juniper Session Smart Router and Session Smart Conductor fails to neutralize special characters in directory names it uses downstream. A local attacker who creates specially named directories and triggers a service restart can unmount arbitrary filesystems or cause a denial of service.","category":"infrastructure","nicknames":[],"who_cares":["juniper","session-smart-router","session-smart-conductor","network-appliance"],"confidence":0.6,"needs_auth":"yes","worst_case":"Attacker unmounts filesystems and crashes the ember service, causing denial of service.","analyst_note":"Find affected and fixed versions and any Juniper advisory (JSA) for CVE-2026-103400 from the NVD entry or Juniper's security bulletins.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["no-local-access"],"who_is_affected":"Teams that run Juniper Session Smart Router or Session Smart Conductor where local users have shell or directory-creation access. The sources do not list affected versions. Deployments without local, non-admin access have a much smaller exposure.","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.00057,"input_tokens":3335,"output_tokens":472,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-103400':15A,18A '-2026':14A,17A 'access':112C 'allow':107C 'applianc':23B 'arbitrari':70B,115C 'attack':57B,109C 'caus':73B,118C 'charact':48B 'compon':90C 'conductor':27B,43B,106C 'crash':11A 'creat':59B 'creation':125C 'cve':13A,16A 'denial':75B,120C 'directori':50B,62B,129C 'downstream':54B,89C 'element':83C 'ember':12A,33B,95C 'fail':44B 'filesystem':9A,71B,116C 'improp':79C 'infrastructur':19B 'inject':91C 'junip':1A,20B,36B,98C 'local':5A,56B,111C 'name':51B,61B,128C 'network':22B,99C 'network-appli':21B 'neutral':46B,80C 'output':85C 'restart':67B,133C 'router':4A,31B,39B,102C 'servic':34B,66B,77B,96C,122C,132C 'session':2A,25B,29B,37B,41B,100C,104C 'session-smart-conductor':24B 'session-smart-rout':28B 'smart':3A,26B,30B,38B,42B,101C,105C 'special':47B,60B,82C,127C 'trigger':64B 'unmount':8A,69B,114C 'use':53B,86C 'user':6A 'via':123C 'vulner':92C","nicknames":[],"mitigations":[],"who_affected":"Teams that run Juniper Session Smart Router or Session Smart Conductor where local users have shell or directory-creation access. The sources do not list affected versions. Deployments without local, non-admin access have a much smaller exposure.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-28T17:17:23+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cvss_by":"sirt@juniper.net","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-103400","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-103400","severity":null,"published_at":"2026-10-28T17:17:23+00:00","modified_at":"2026-10-28T17:17:23+00:00","first_seen_at":"2026-10-28T17:34:08+00:00","fetched_at":"2026-10-28T17:34:08+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"}