Is CVE-2026-103391 being exploited?

No public exploit is currently tracked.

How severe is CVE-2026-103391?

CVE-2026-103391 has a CVSS v3 severity of MEDIUM (5.3).

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CVE-2026-103391

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.