VDB-428042 · CVE-2026-103391 · GCVE-0-2026-103391

Juniper Networks Session Smart Router up to 7.0.4/7.1.6/7.2.2 TCP Proxy out-of-bounds write

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.2	$0-$5k	1.15-

Summaryinfo

A vulnerability was found in Juniper Networks Session Smart Router up to 7.0.4/7.1.6/7.2.2. It has been declared as problematic. Affected is an unknown function of the component TCP Proxy. Such manipulation leads to out-of-bounds write. This vulnerability is uniquely identified as CVE-2026-103391. The attack can be launched remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Juniper Networks Session Smart Router up to 7.0.4/7.1.6/7.2.2. Affected by this issue is some unknown processing of the component TCP Proxy. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. Using CWE to declare the problem leads to CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. Impacted is integrity. CVE summarizes:

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.

The advisory is available at supportportal.juniper.net. This vulnerability is handled as CVE-2026-103391 since 09/30/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 10/28/2026).

Upgrading to version 7.0.5, 7.1.7 or 7.2.3 eliminates this vulnerability.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

Router Operating System

Vendor

Juniper Networks

Name

Session Smart Router

Version

License

commercial

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.2

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 5.3
CNA Vector (juniper): 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Session Smart Router 7.0.5/7.1.7/7.2.3

Timelineinfo

09/30/2026 CVE reserved
10/28/2026 +28 days Advisory disclosed
10/28/2026 +0 days VulDB entry created
10/28/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: supportportal.juniper.net
Status: Confirmed

CNA: juniper
CVE: CVE-2026-103391 (🔒)

GCVE (CVE): GCVE-0-2026-103391
GCVE (VulDB): GCVE-100-428042

Entryinfo

Created: 10/28/2026 18:02
Changes: 10/28/2026 18:02 (64)
Complete: 🔍
Cache ID: 216::103