Junos OS CVE-2026-102050

The target interface must be explicitly configured for LLDP - an interface without LLDP enabled is not reachable by this vector. The attacker must be Layer 2 adjacent (AV:A): on the same broadcast domain or directly connected to the LLDP-enabled interface, since LLDP is link-local and not routable across L3 boundaries. No authentication is required (PR:N) and no user interaction (UI:N), but the adjacency and LLDP-enabled prerequisites are the primary limiting factors, confining exploitation to attackers who already have local network presence; remote Internet-based exploitation is not possible.

This is a credible operational priority for Juniper-heavy networks, but the real-world risk is bounded by the attack vector rather than severity theater. The vendor CVSS 4.0 vector scores 8.7 (High) with AV:A (adjacent), AC:L, PR:N and UI:N, meaning an unauthenticated attacker on the same Layer 2 segment can trigger it reliably with no interaction - a genuinely low bar for anyone already on the local broadcast domain. However, the impact is a denial of service in the l2cpd daemon, and here the input signals CONFLICT: the vendor vector asserts VC:H/VI:H/VA:H (full confidentiality and integrity loss), yet the description describes only disruption of LLDP and other Layer 2 control-plane protocols - a classic availability-only DoS. The C/I:H claims appear inconsistent with a stack buffer overflow that the vendor characterizes as DoS; verify with Juniper whether code execution is actually achievable before treating this as a confidentiality/integrity breach. No EPSS score, no CISA KEV listing, and no public exploit were provided, so there is no evidence of active or widespread exploitation; the adjacency requirement further argues against opportunistic mass exploitation and toward insider or lateral-movement scenarios. Net: patch promptly on exposed Junos/Junos Evolved devices with LLDP-enabled interfaces, but treat the headline 8.7 as attack-vector-driven, not exploitation-driven.

An attacker with a foothold on the same Layer 2 segment (e.g., a compromised host or rogue device on a directly connected interface) sends specially crafted LLDP frames to a Junos interface that has LLDP enabled. The malformed packets overflow a stack buffer in the l2cpd daemon, crashing Layer 2 control-plane processing; repeated frames sustain the outage and degrade LLDP and other L2 control protocols across the device. No public exploit code was identified at time of analysis, and the adjacency requirement means the attacker must already be on the local network.