Medium 5.3Published Oct 28, 2026

CVE-2026-103391Session Smart Router: An attacker-controlled TCP option causes an out-of-bounds write when using the TCP proxy feature

Updated under an hour ago (Oct 30, 2026, 5:50 AM ET)

Does this affect you?

It affects Juniper Networks Session Smart Router. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

Do this next

Start free and add your stackFree account, 3 products Every CVE for Juniper Networks Session Smart Router Exploited in the last 30 days

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: 5.3 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Weakness (CWE): CWE-787
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: juniper
NVD analysis: Awaiting Analysis
Record last updated: Oct 28, 2026
First seen by InfoSec Signals: Oct 28, 2026

Affected products

Affected products

Juniper Networks Session Smart Router juniper_networks:session_smart_router (from the name)	before 7.0.5; from 7.1.0 before 7.1.7; from 7.2.0 before 7.2.3	CNA record

References

References

https://supportportal.juniper.net/JSA112183	vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.