---
id: "CVE-2026-103401"
kind: "vulnerability"
aliases: ["CVE-2026-103401"]
title: "Juniper Session Smart Router: link following lets local users overwrite root files"
severity: "high"
cvss: 8.8
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: [{"name": "Session Smart Router", "fixed": ["7.0.5", "7.1.7", "7.2.3"], "affected": "< 7.0.5, < 7.1.7, < 7.2.3 (per release train)", "ecosystem": "vendor"}, {"name": "Session Smart Conductor", "fixed": ["7.0.5", "7.1.7", "7.2.3"], "affected": "< 7.0.5, < 7.1.7, < 7.2.3 (per release train)", "ecosystem": "vendor"}]
ecosystems: []
tags: ["infrastructure", "juniper", "mist", "network-appliance", "session-smart-conductor", "session-smart-router"]
not_affected_if: ["managed-by-conductor"]
published_at: "2026-10-28T17:17:24+00:00"
first_seen_at: "2026-10-28T17:34:08+00:00"
updated_at: "2026-10-28T17:38:33+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-103401", "first_seen_at": "2026-10-28T17:34:08+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-10-28T17:38:33+00:00"}]
---

# Juniper Session Smart Router: link following lets local users overwrite root files

Juniper Session Smart Router and Conductor web server handlers follow symbolic links before writing files. A local unprivileged user can overwrite arbitrary files as root through unauthenticated API endpoints.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Session Smart Router affected < 7.0.5, < 7.1.7, < 7.2.3 (per release train) fixed 7.0.5, 7.1.7, 7.2.3
- vendor:Session Smart Conductor affected < 7.0.5, < 7.1.7, < 7.2.3 (per release train) fixed 7.0.5, 7.1.7, 7.2.3

## How to check

- Inventory every Session Smart Router and Session Smart Conductor and read its software version.
- Any version before 7.0.5 (7.0 train), 7.1.7 (7.1 train) or 7.2.3 (7.2 train) is affected; Juniper says all versions before these are affected.
- Exposure requires a low-privilege account or access to the device's management/API interface; restrict that access until patched.
- The earlier claim that Conductor-managed routers are unaffected is not in Juniper's bulletin; do not rely on it.

## Fix

Upgrade Session Smart Router and Conductor to 7.0.5, 7.1.7, 7.2.3 or any later release. No workaround exists per Juniper. Releases past EOE/EOL are not evaluated, so move to a supported train.

## Timeline

- 2026-10-28T17:34:08+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-103401
- 2026-10-28T17:38:33+00:00 analyst — Read Juniper JSA112183 (2026-10-28) in browser: all SSR/Conductor before 7.0.5, 7.1.7, 7.2.3 affected; CVSS 8.8 AV:N/PR:L (low-privilege authenticated, network-reachable, not purely local as triage said); no workarounds; no known exploitation. Exact endpoints and the Mist/Conductor-managed exclusion are NOT in the bulletin, so left unverified.

## Documents

- [advisory] JSA112183 Juniper 2026-10 On-Demand Security Bulletin: SSR and Conductor https://supportportal.juniper.net/s/article/2026-10-On-Demand-Security-Bulletin-Session-Smart-Router-and-Session-Smart-Conductor-Multiple-internally-discovered-vulnerabilities-resolved

## From the sources

An Improper Link Resolution Before File Access ('Link Following') vulnerability in the unauthenticated web server handlers in Juniper Networks Session Smart Router and Session Smart Conductor allows a local unprivileged user to overwrite arbitrary files as root via unauthenticated API endpoints.

This vulnerability can be exploited on Mist-managed routers and on unmanaged Routers that have not yet been onboarded to a Conductor. Routers already managed by Conductor are not affected.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_