Junos OS EUVD-2026-101412

Exploitation requires that the target Junos OS / Junos OS Evolved device has OSPFv2 configured and running on at least one interface, and that the attacker can send packets onto that OSPF-enabled interface's broadcast/adjacent segment (Layer 2 adjacency or an OSPF neighbor relationship). No authentication (PR:N) and no user interaction (UI:N) are needed, but the AV:A adjacency requirement is the primary limiting factor: the attacker cannot reach the daemon from an arbitrary remote Internet location and must be on or able to inject onto the OSPF-speaking network. Devices without OSPFv2 enabled are not exploitable. Fixed releases are listed per train (e.g., 23.2R2-S7.7, 24.4R2-S5, 25.2R2-S2 and the corresponding -EVO builds).

This is a credible but bounded operational risk rather than a top-tier emergency. The CVSS 4.0 vector (AV:A/AC:L/AT:N/PR:N/UI:N) confirms an unauthenticated attacker with low complexity and no user interaction can trigger it, but only from an adjacent position (AV:A) - the attacker must already be on an OSPF-speaking network segment, which sharply narrows the realistic threat population to insiders, compromised adjacent devices, or attackers who have already gained a foothold on the routing fabric. Impact is availability-only (VC:N/VI:N/VA:H with SA:L), consistent with a routing-daemon crash/DoS and no confidentiality or integrity exposure. No EPSS score was provided, and there is no CISA KEV listing and no public exploit in the supplied data, so exploitation status is 'no public exploit identified at time of analysis.' A vendor patch is available and the flaw was reported by Juniper itself, indicating coordinated disclosure rather than observed in-the-wild abuse. Net: prioritize patching on internet-adjacent or multi-tenant routing edges where OSPF trust boundaries are weak, but this is not a widely-weaponizable remote-internet threat given the adjacency requirement. No EPSS/KEV data was supplied, so widespread-exploitation likelihood cannot be quantified from the input.

An attacker positioned on a network segment that participates in OSPFv2 (e.g., a compromised adjacent router, server, or rogue device on an OSPF-enabled VLAN) crafts and sends specific malformed OSPFv2 packets to a vulnerable Junos OS or Junos OS Evolved device. The packets trigger an integer overflow in the routing protocol daemon (rpd), crashing it and causing a denial of service that disrupts routing. No authentication or user interaction is required, but the attacker must have adjacent (Layer 2 / same OSPF domain) access; no public exploit code was identified in the provided data.