Session Smart Router: Stack-based Buffer Overflow
CVE-2026-103408 is a high-severity stack-based buffer overflow vulnerability in Session Smart Router from Juniper Networks, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists versions 7.0.5, 7.1.7, 7.2.3 as the first without the flaw, so updating Session Smart Router to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.31% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Session Smart Router to 7.0.5 or 7.1.7 or 7.2.3, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Juniper Networks | Session Smart Router | before 7.0.5; 7.1.0 up to, but not including, 7.1.7; 7.2.0 up to, but not including, 7.2.3 | 7.0.5, 7.1.7, 7.2.3 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- AdjacentThe attacker must be on the same local network segment.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (juniper.net).
Official description
A Stack Buffer Overflow vulnerability in the DHCP client in Juniper Networks Session Smart Router allows an unauthenticated attacker on the local network to achieve remote code execution via a malicious DHCP reply.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Stack-based Buffer Overflow
The product writes past the end of a buffer that was allocated on the stack.
How developers prevent this class of flaw
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
- Use an abstraction library to abstract away risky APIs. Not a complete solution.
- Implement and perform bounds checking on input.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in Session Smart Router
- 8.8 High severity
- 7.1 High severity
- 7.5 High severity
- 9.8 Critical severity
- 8.8 High severity
- 8.8 High severity
Recent Stack-based Buffer Overflow vulnerabilities
- 8.8 High severity
- 8.0 High severity
- 8.0 High severity
- 8.8 High severity
- 9.8 Critical severity
- 7.1 High severity
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