CVE-2026-103409: Juniper Networks Session Smart Router (Critical, CVSS 9.8)
- CVSS
- 9.8 Critical (v3.1)
- EPSS
- 0.3% chance of exploitation in the next 30 days (higher than 28.3% of CVEs)
- Exploited in the wild
- Not on CISA’s KEV list
- Public exploit
- None reported in public exploit databases
- Weakness
- CWE-306
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- Published
- Oct 28, 2026
What it is
A Missing authentication for critical function vulnerability in Juniper Networks Session Smart Router allows an unauthenticated network-based attacker to obtain administrative privileges by passing crafted URL parameters to an insecure endpoint running as root. Note that this vulnerability can only be exploited prior to the device being onboarded to Mist/Conductor. The issue can no longer be exploited once a device is onboarded to Mist/Conductor.
Description from the National Vulnerability Database.
What to do
Check whether you run Juniper Networks Session Smart Router, then apply the vendor’s fix or mitigation from the advisories below.
Sources: NVD, FIRST EPSS, CISA KEV, and public exploit databases (availability only). ThreatRoundup reports whether public exploit code exists but never links to it: fake proof-of-concepts that infect security researchers are common. This page updates automatically.