CyberSecBulletin
CVE-2026-103401NVD status: Awaiting Analysis

Session Smart Router: Improper Link Resolution Before File Access

Published Updated By the CyberSecBulletin desk

CVE-2026-103401 is a high-severity improper link resolution before file access vulnerability in Session Smart Router from Juniper Networks, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists versions 7.0.5, 7.1.7, 7.2.3 as the first without the flaw, so updating Session Smart Router to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.34% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Session Smart Router to 7.0.5 or 7.1.7 or 7.2.3, whichever matches your release line, or a later version.
  2. Update Session Smart Conductor to 7.0.5 or 7.1.7 or 7.2.3, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
Juniper NetworksSession Smart Routerbefore 7.0.5; 7.1.0 up to, but not including, 7.1.7; 7.2.0 up to, but not including, 7.2.37.0.5, 7.1.7, 7.2.3
Juniper NetworksSession Smart Conductorbefore 7.0.5; 7.1.0 up to, but not including, 7.1.7; 7.2.0 up to, but not including, 7.2.37.0.5, 7.1.7, 7.2.3

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (juniper.net).

Official description

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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Link Resolution Before File Access

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

How developers prevent this class of flaw

  • Follow the principle of least privilege when assigning access rights to entities in a software system. Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

More Improper Link Resolution Before File Access vulnerabilities (CWE-59)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Session Smart Router

All Session Smart Router vulnerabilities

Recent Improper Link Resolution Before File Access vulnerabilities

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