CVE-2026-103391: medium-severity vulnerability in Juniper Networks Session Smart Router
Session Smart Router: An attacker-controlled TCP option causes an out-of-bounds write when using the TCP proxy feature
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.3epss 0.2%
An Out-of-bounds Write vulnerability in the SSR TCP proxy/optimization path in Juniper Networks Session Smart Router allows an attacker to corrupt forwarded packet data and potentially cause a data-plane crash via a transit TCP packet with a crafted TCP option length.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Affected products
Juniper Networks · Session Smart RouterRelated CVEs — Juniper Networks Session Smart Router
In the same product, most dangerous first.
CVE-2025-21589CRITICALSession Smart Router, Session Smart Conductor, WAN Assurance Router: API Authentication Bypass vulnerabilityEPSS 1.5%CVE-2026-106079HIGHSession Smart Router and Session Smart Conductor: Improper validation of a field causes privilege escalation when updating the YANG configurationEPSS 1.2%CVE-2026-103403HIGHSession Smart Router and Session Smart Conductor: Unvalidated input causes arbitrary file deletion and command execution when deleting audit rulesEPSS 1.2%CVE-2024-2973CRITICALSession Smart Router(SSR): On redundant router deployments API authentication can be bypassedEPSS 1.1%CVE-2026-103390MEDIUMSession Smart Router and Session Smart Conductor: A malformed HTTP URI causes a service crash during HTTP application identificationEPSS 0.4%CVE-2026-103409CRITICALSession Smart Router: An attacker obtains administrative privileges when an unauthenticated internal endpoint is accessedEPSS 0.3%