All vulnerabilities
CVE-2026-103391

Session Smart Router: An attacker-controlled TCP option causes an out-of-bounds write when using the TCP proxy feature

Juniper Networks Session Smart RouterNetwork & edge
Open in ThreatlineRecord JSON
CVSS
5.3Medium
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)No scoreNo FIRST EPSS score in this snapshot yet
Fixed in7.0.5Also 7.1.7, 7.2.3CVE List
Published28 Oct 2026Updated 28 Oct 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

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.

Text from CVE List

Affected versions 3

  • Session Smart Routeraffected: all versions before 7.0.5CVE List
  • Session Smart Routeraffected: 7.1.0 before 7.1.7CVE List
  • Session Smart Routeraffected: 7.2.0 before 7.2.3CVE List

References 1