CVE-2026-33781
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
An Improper Check for Unusual or Exceptional Conditions vulnerability in the packet forwarding engine (pfe) of Juniper Networks Junos OS on specific EX and QFX Series devices allow an unauthenticated, adjacent attacker to cause a complete Denial of Service (DoS).
On EX4k, and QFX5k platforms configured as service-provider edge devices, if L2PT is enabled on the UNI and VSTP is enabled on NNI in VXLAN scenarios, receiving VSTP BPDUs on UNI leads to packet buffer allocation failures, resulting in the device to not pass traffic anymore until it is manually recovered with a restart.This issue affects Junos OS:
- 24.4 releases before 24.4R2,
- 25.2 releases before 25.2R1-S1, 25.2R2.
This issue does not affect Junos OS releases before 24.4R1.
Affected Software
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Juniper Networks | Junos OS | 24.4 < 24.4R2 | affected |
| Juniper Networks | Junos OS | 25.2 < 25.2R1-S1, 25.2R2 | affected |
| Juniper Networks | Junos OS | 0 < 24.4R1 | unaffected |
Weaknesses
- CWE-754: CWE-754 Improper Check for Unusual or Exceptional Conditions
Workarounds
To prevent VSTP BPDUs from being processed on UNI interfaces configure:
[ protocols layer2-control bpdu-block interface all drop ]
ADP Enrichment
CISA ADP Vulnrichment
- SSVC:
- Exploitation: none
- Automatable: no
- Technical Impact: partial
References
Feedback
Was this page helpful?
Glad to hear it! Please tell us how we can improve.
Sorry to hear that. Please tell us how we can improve.