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.
Fix
Patch, vendor advisory and mitigation references on NVD 1
- https://kb.juniper.net/JSA107869 Mitigation, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 7.1 · juniperNVD modified 2026-10-26 22:10
Affected (CPE criteria) 7
cpe:2.3:o:juniper:junos:24.4:-:*:*:*:*:*:*cpe:2.3:o:juniper:junos:24.4:r1:*:*:*:*:*:*cpe:2.3:o:juniper:junos:24.4:r1-s2:*:*:*:*:*:*cpe:2.3:o:juniper:junos:24.4:r1-s3:*:*:*:*:*:*cpe:2.3:o:juniper:junos:25.2:-:*:*:*:*:*:*cpe:2.3:o:juniper:junos:25.2:r1:*:*:*:*:*:*cpe:2.3:o:juniper:junos:25.2:r2:*:*:*:*:*:*
References 1
- https://kb.juniper.net/JSA107869 Mitigation, Vendor Advisory