Vulnerability · Published Oct 28, 2026 · Assigned by juniper
CVE-2026-103391Session Smart Router: An attacker-controlled TCP option causes an out-of-bounds write when using the TCP proxy feature
Medium 5.3
In plain English
A medium-severity out-of-bounds write in Session Smart Router from Juniper Networks. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 11% of all known vulnerabilities).
Severity (CVSS 3.1)5.3Medium
Exploit odds (30 days)0.2%top 89.2% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Juniper Networks | Session Smart Router | 0 – before 7.0.57.1.0 – before 7.1.77.2.0 – before 7.2.3 |
Weakness: CWE-787 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
References
- https://supportportal.juniper.net/JSA112183 vendor-advisory