---
id: "CVE-2026-103393"
kind: "vulnerability"
aliases: ["CVE-2026-103393"]
title: "Juniper Session Smart Router: VRRP flaw leaks memory or crashes the device"
severity: "medium"
cvss: 4.3
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["infrastructure", "juniper", "network", "session-smart-router", "vrrp"]
not_affected_if: ["vrrp-not-configured"]
published_at: "2026-10-28T17:17:22+00:00"
first_seen_at: "2026-10-28T17:34:08+00:00"
updated_at: "2026-10-28T17:34:43+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-103393", "first_seen_at": "2026-10-28T17:34:08+00:00"}]
---

# Juniper Session Smart Router: VRRP flaw leaks memory or crashes the device

A crafted VRRPv3 advertisement sent from the same Layer 2 network triggers an out-of-bounds read in Juniper's Session Smart Router VRRP code. An attacker can read stale memory contents or make the system fault.

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

## How to check

- Check the installed Session Smart Router software version against Juniper's advisory: unknown
- Confirm whether VRRP is enabled on the router's interfaces: unknown

## Fix

- Move Session Smart Router to the fixed release named in Juniper's advisory: unknown

## Timeline

- 2026-10-28T17:34:08+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-103393

## From the sources

An Out-of-Bounds Read vulnerability in the VRRP implementation in Juniper Networks Session Smart Router allows an L2-adjacent attacker to read stale memory contents or cause a system fault via a specially crafted VRRPv3 advertisement.

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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_