Quick answers
- Is CVE-2026-103393 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-103393 being exploited in the wild.
- How severe is CVE-2026-103393?
- Medium severity, with a CVSS score of 4.3, published 28 October 2026.
- Which products and versions are affected?
- Juniper Networks Session Smart Router.
- Is there a fix for CVE-2026-103393?
- 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-2026-103393 attacked?
- It is attacked from the adjacent network, in a network appliance.
- Am I affected by CVE-2026-103393?
- Check whether you run Juniper Networks Session Smart Router. 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
The VRRP (Virtual Router Redundancy Protocol) implementation in Session Smart Router contains an out-of-bounds read flaw triggered by malformed VRRPv3 advertisements. An L2-adjacent attacker can craft and transmit a specially crafted advertisement to read stale memory or induce a system fault without requiring authentication or user interaction, potentially leaking sensitive data or causing denial of service.
Affected products
- Juniper Networks Session Smart Router
Timeline
- 2026-10-28: disclosed