CVE-2026-101972 Juniper Networks CVE debrief

Who should care

Junos OS and Junos OS Evolved administrators and network security teams should review and apply security patches, verify OSPF-enabled interfaces, and monitor network traffic for suspicious OSPFv2 packets. Affected operators, platforms, and vulnerability-management teams should prioritize patching and verify OSPF-enabled interfaces. Security teams should monitor network traffic and review compensating controls for exposed systems.

Why it matters

CVE-2026-101972 is a medium-severity vulnerability in Junos OS and Junos OS Evolved that can cause denial of service via specific OSPFv2 packets. Junos OS and Junos OS Evolved administrators and network security teams should review and apply security patches, verify OSPF-enabled interfaces, and monitor network traffic.

• Denial of service via specific OSPFv2 packets
• Potential routing disruptions on OSPF-enabled interfaces

Technical summary

An Integer Overflow or Wraparound vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated adjacent attacker to cause a denial of service via specific OSPFv2 packets sent on an OSPF-enabled interface. This vulnerability affects Junos OS and Junos OS Evolved, potentially disrupting routing when OSPF is enabled. The vulnerability is caused by an integer overflow or wraparound in the rpd, which can be triggered by specific OSPFv2 packets. To mitigate this vulnerability, administrators should review and apply security patches, verify OSPF-enabled interfaces, and monitor network traffic.

Defensive priority

Medium priority for Junos OS and Junos OS Evolved administrators

Recommended defensive actions

• Review and apply Juniper Networks' security patches for affected Junos OS and Junos OS Evolved versions
• Verify OSPF-enabled interfaces and restrict access to them if possible
• Monitor network traffic for suspicious OSPFv2 packets
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record and source item provide details on the Integer Overflow or Wraparound vulnerability in Junos OS and Junos OS Evolved. The vulnerability allows an unauthenticated adjacent attacker to cause a denial of service via specific OSPFv2 packets sent on an OSPF-enabled interface. Evidence is limited to the CVE record and source item, and defenders should verify OSPF-enabled interfaces and monitor network traffic for suspicious OSPFv2 packets.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.