CVE-2026-103993: CWE-787 Out-of-bounds Write in Juniper Networks Junos OS

This vulnerability is an out-of-bounds write (CWE-787) in the routing protocol daemon (rpd) component of Juniper Networks Junos OS and Junos OS Evolved. It is triggered when an adjacent attacker sends a crafted set of BGP communities that includes the graceful-shutdown sender community during advertisement attempts. This causes the rpd process to crash, leading to a denial-of-service condition. The vulnerability affects multiple versions across several Junos OS release trains and their Evolved variants, as detailed in the affectedVersions field. The CVSS 3.1 vector indicates the attack requires adjacent network access, low attack complexity, low privileges, no user interaction, and impacts availability with no confidentiality or integrity impact.

Successful exploitation results in a denial-of-service condition due to the crash of the routing protocol daemon (rpd). This disrupts routing operations on affected Junos OS devices, potentially impacting network availability. There is no indication of confidentiality or integrity compromise. No known exploits are reported in the wild at this time.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since no official patch or workaround information is provided, users should monitor Juniper Networks advisories for updates. Network operators may consider restricting or monitoring BGP community attributes from adjacent peers as a temporary mitigation until an official fix is available.