Junos OS vulnerability

A Stack-based Buffer Overflow vulnerability in the UTM Anti-Spam SBL of Juniper Networks Junos OS on SRX series allows an unauthenticated remote attacker to cause arbitrary code execution or a denial of service via a injected malformed DNS packet when Anti-Spam SBL inspection is enabled.

Published 14 Oct 2026Updated 16 Oct 20261 sources
CVSS 9.2

What happened

A Stack-based Buffer Overflow vulnerability in the UTM Anti-Spam SBL of Juniper Networks Junos OS on SRX series allows an unauthenticated remote attacker to cause arbitrary code execution or a denial of service via a injected malformed DNS packet when Anti-Spam SBL inspection is enabled.

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) 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.