What is CVE-2026-103393?

CVE-2026-103393 is a medium-severity vulnerability in Juniper Networks Session Smart Router, classified under Out-of-bounds Read. CVSS score: 4.3/10. Published 2026-10-28.

How severe is CVE-2026-103393?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Out-of-bounds Read in Juniper Networks Session Smart Router

CVE-2026-103393

An Out-of-Bounds Read vulnerability in the VRRP implementation in Juniper Networks Session Smart Router allows an L2-adjacent attacker to read stale memory contents or cause a system fault via a specially crafted VRRPv3 advertisement.

Vulnerability class: Buffer Overflow

Published 2026-10-28 · last modified 2026-10-28.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Juniper Networks Session Smart Router

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

supportportal.juniper.net/JSA112183 (vendor-advisory)

Frequently asked questions

What is CVE-2026-103393?: CVE-2026-103393 is a medium-severity vulnerability in Juniper Networks Session Smart Router, classified under Out-of-bounds Read. CVSS score: 4.3/10. Published 2026-10-28.
How severe is CVE-2026-103393?: Medium severity. CVSS v3 base score is 4.3 out of 10.