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CVE-2026-33781

Full vulnerability record from the local CVENow database.

Description

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.

Severity
HIGH
CVSS score
7.1 (v4.0)
Vulnerability status
Analyzed
Source identifier
[email protected]
Published
2026-04-09 22:16:27.193000
Last modified
2026-10-26 22:10:00.163000
View original CVE JSON 
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  "id": "CVE-2026-33781",
  "sourceIdentifier": "[email protected]",
  "published": "2026-04-09T22:16:27.193",
  "lastModified": "2026-10-26T22:10:00.163",
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      "value": "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).\n\nOn 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:\n\n\n\n  *  24.4 releases before 24.4R2,\n  *  25.2 releases before 25.2R1-S1, 25.2R2.\n\n\n\n\nThis issue does not affect Junos OS releases before 24.4R1."
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