CVE-2026-101970: CWE-416 Use After Free in Juniper Networks Junos OS

This vulnerability (CVE-2026-101970) involves a Use After Free condition in the rpd process handling PIM Join/Prune messages on Juniper Networks Junos OS and Junos OS Evolved platforms. An unauthenticated attacker with adjacent network access can send crafted PIM messages to trigger a crash of the routing daemon (rpd) when sparse mode PIM is enabled. The issue affects a range of Junos OS versions prior to certain maintenance releases across multiple branches, including both standard and evolved variants. The CVSS 3.1 vector indicates the attack requires adjacent network access, no privileges, and no user interaction, with a low attack complexity and impacts availability only.

Successful exploitation results in a denial of service condition by crashing the routing daemon (rpd), which can disrupt routing functions on affected Junos OS devices. There is no indication of confidentiality or integrity impact. The vulnerability requires adjacency on the network and no authentication, making it a risk primarily for network environments where an attacker can send PIM messages directly to the device.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, consider disabling sparse mode PIM if feasible or restricting access to PIM traffic to trusted network segments to reduce exposure. Monitor Juniper Networks advisories for updates and apply patches promptly once released.