Quick answers
- Is CVE-2026-103411 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-103411 being exploited in the wild.
- How severe is CVE-2026-103411?
- High severity, with a CVSS score of 7.1, published 28 October 2026.
- Which products and versions are affected?
- Juniper Networks Session Smart Router <UNKNOWN>.
- Is there a fix for CVE-2026-103411?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-103411 attacked?
- It is attacked from the adjacent network, in a network appliance.
- Am I affected by CVE-2026-103411?
- Check whether you run Juniper Networks Session Smart Router at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
An integer underflow vulnerability exists in the DhcpMessageDecoder component of Session Smart Router, triggered by processing a malicious DHCP reply. The flaw can be exploited by an attacker with adjacent network access to trigger information disclosure or denial of service. No authentication is required; the attack relies on sending a specially crafted DHCP response to the vulnerable router.
Affected products
- Juniper Networks Session Smart Router <UNKNOWN>
Timeline
- 2026-10-28: disclosed