CVE-2026-33781
Improper Condition Check in Junos PFE Causes DoS
Publication date: 2026-04-09
Last updated on: 2026-04-17
Assigner: Juniper Networks, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| juniper | junos | 24.4 |
| juniper | junos | 24.4 |
| juniper | junos | 24.4 |
| juniper | junos | 24.4 |
| juniper | junos | 25.2 |
| juniper | junos | 25.2 |
| juniper | junos | 25.2 |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-754 | The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability is an Improper Check for Unusual or Exceptional Conditions in the packet forwarding engine (pfe) of Juniper Networks Junos OS on certain EX and QFX Series devices.
Specifically, on EX4k and QFX5k platforms configured as service-provider edge devices, if L2PT is enabled on the UNI and VSTP is enabled on the NNI in VXLAN scenarios, receiving VSTP BPDUs on the UNI interface causes packet buffer allocation failures.
This leads to the device being unable to pass traffic until it is manually recovered with a restart.
The vulnerability allows an unauthenticated, adjacent attacker to cause a complete Denial of Service (DoS).
How can this vulnerability impact me? :
The vulnerability can cause a complete Denial of Service (DoS) on affected Juniper EX and QFX Series devices.
When exploited, the device will stop passing traffic due to packet buffer allocation failures triggered by receiving certain VSTP BPDUs.
This results in network downtime until the device is manually restarted to recover.