Junos OS vulnerability

A Stack-based Buffer Overflow vulnerability in the phone-home daemon (phcd) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent unauthenticated attacker to execute arbitrary code as root via a crafted DHCP SZTP bootstrap message. This issue only affects platforms that support Secure-ZTP.

Published 14 Oct 2026Updated 16 Oct 20261 sources
CVSS 8.7

What happened

A Stack-based Buffer Overflow vulnerability in the phone-home daemon (phcd) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent unauthenticated attacker to execute arbitrary code as root via a crafted DHCP SZTP bootstrap message. This issue only affects platforms that support Secure-ZTP.

Affected versions

Junos OS: before 23.2R2-S7.7 (custom); 23.4 through before 23.4R2-S8.13 (custom); 24.2 through before 24.2R2-S5.5 (custom); 24.4 through before 24.4R2-S5 (custom); 25.2 through before 25.2R2-S2 (custom); 25.4 through before 25.4R1-S3 (custom); 26.2 through before 26.2R1-S2 (custom); before 23.2R2-S7.7-EVO (custom); 23.4 through before 23.4R2-S8.11-EVO (custom); 24.2 through before 24.2R2-S5.6-EVO (custom); 24.4 through before 24.4R2-S5-EVO (custom); 25.2 through before 25.2R2-S2-EVO (custom); 25.4 through before 25.4R1-S3-EVO (custom); 26.2 through before 26.2R1-S2-EVO (custom); 23.4X100 (custom); 25.2X100 through before 25.2X100-D35-EVO (custom); 25.4X300 through before 25.4X300-D40-EVO (custom) Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references

No public PoC reference has passed the current publication threshold.