Junos OS: EX4k Series, QFX5k Series: In an EVPN-VXLAN configuration link flaps cause Inter-VNI traffic drop (Juniper Networks Junos OS)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.26 % · percentile 18 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- juniper
- NVD status
- Analyzed
Description
An Improper Check for Unusual or Exceptional Conditions vulnerability in the packet forwarding engine (PFE) of Juniper Networks Junos OS on EX4k Series and QFX5k Series platforms allows an unauthenticated network-adjacent attacker flapping an interface to cause traffic between VXLAN Network Identifiers (VNIs) to drop, leading to a Denial of Service (DoS). On all EX4k and QFX5k platforms, a link flap in an EVPN-VXLAN configuration Link Aggregation Group (LAG) results in Inter-VNI traffic dropping when there are multiple load-balanced next-hop routes for the same destination. This issue is only applicable to systems that support EVPN-VXLAN Virtual Port-Link Aggregation Groups (VPLAG), such as the QFX5110, QFX5120, QFX5200, EX4100, EX4300, EX4400, and EX4650. Service can only be restored by restarting the affected FPC via the 'request chassis fpc restart slot <slot-number>' command. This issue affects Junos OS on EX4k and QFX5k Series: * all versions before 21.4R3-S12, * all versions of 22.2 * from 22.4 before 22.4R3-S8, * from 23.2 before 23.2R2-S5, * from 23.4 before 23.4R2-S5, * from 24.2 before 24.2R2-S3, * from 24.4 before 24.4R2.
Weaknesses (CWE)
- CWE-754 — Improper Check for Unusual or Exceptional Conditions
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 6.5 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | juniper |
| CVSS 4.0 | HIGH 7.1 | CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:U/RE:M/U:Green | juniper |
| CVSS 4.0 | HIGH 7.1 | CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:U/V:X/RE:M/U:Green | NVD · sirt@juniper.net (Secondary) |
| CVSS 3.1 | MEDIUM 6.5 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · sirt@juniper.net (Secondary) |
European references
- ENISA EUVD · EUVD-2026-2694
- GCVE · GCVE-0-2026-21910
CERT-FR advisories
- CERTFR-2026-AVI-0050 — Multiples vulnérabilités dans les produits Juniper Networks · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:*< 21.4cpe:2.3:o:juniper:junos:21.4:-:*:*:*:*:*:*cpe:2.3:o:juniper:junos:21.4:r1:*:*:*:*:*:*cpe:2.3:o:juniper:junos:21.4:r1-s1:*:*:*:*:*:*cpe:2.3:o:juniper:junos:21.4:r1-s2:*:*:*:*:*:*cpe:2.3:o:juniper:junos:21.4:r2:*:*:*:*:*:*cpe:2.3:o:juniper:junos:21.4:r2-s1:*:*:*:*:*:*cpe:2.3:o:juniper:junos:21.4:r2-s2:*:*:*:*:*:*cpe:2.3:o:juniper:junos:21.4:r3:*:*:*:*:*:*cpe:2.3:o:juniper:junos:21.4:r3-s1:*:*:*:*:*:*cpe:2.3:o:juniper:junos:21.4:r3-s10:*:*:*:*:*:*cpe:2.3:o:juniper:junos:21.4:r3-s11:*:*:*:*:*:*cpe:2.3:o:juniper:junos:21.4:r3-s2:*:*:*:*:*:*cpe:2.3:o:juniper:junos:21.4:r3-s3:*:*:*:*:*:*cpe:2.3:o:juniper:junos:21.4:r3-s4:*:*:*:*:*:*cpe:2.3:o:juniper:junos:21.4:r3-s5:*:*:*:*:*:*cpe:2.3:o:juniper:junos:21.4:r3-s6:*:*:*:*:*:*cpe:2.3:o:juniper:junos:21.4:r3-s7:*:*:*:*:*:*cpe:2.3:o:juniper:junos:21.4:r3-s8:*:*:*:*:*:*cpe:2.3:o:juniper:junos:21.4:r3-s9:*:*:*:*:*:*cpe:2.3:o:juniper:junos:22.2:*:*:*:*:*:*:*cpe:2.3:o:juniper:junos:22.4:-:*:*:*:*:*:*cpe:2.3:o:juniper:junos:22.4:r1:*:*:*:*:*:*cpe:2.3:o:juniper:junos:22.4:r1-s1:*:*:*:*:*:*cpe:2.3:o:juniper:junos:22.4:r1-s2:*:*:*:*:*:*cpe:2.3:o:juniper:junos:22.4:r2:*:*:*:*:*:*cpe:2.3:o:juniper:junos:22.4:r2-s1:*:*:*:*:*:*cpe:2.3:o:juniper:junos:22.4:r2-s2:*:*:*:*:*:*cpe:2.3:o:juniper:junos:22.4:r3:*:*:*:*:*:*cpe:2.3:o:juniper:junos:22.4:r3-s1:*:*:*:*:*:*cpe:2.3:o:juniper:junos:22.4:r3-s2:*:*:*:*:*:*cpe:2.3:o:juniper:junos:22.4:r3-s3:*:*:*:*:*:*cpe:2.3:o:juniper:junos:22.4:r3-s4:*:*:*:*:*:*cpe:2.3:o:juniper:junos:22.4:r3-s5:*:*:*:*:*:*cpe:2.3:o:juniper:junos:22.4:r3-s6:*:*:*:*:*:*cpe:2.3:o:juniper:junos:22.4:r3-s7:*:*:*:*:*:*cpe:2.3:o:juniper:junos:23.2:-:*:*:*:*:*:*cpe:2.3:o:juniper:junos:23.2:r1:*:*:*:*:*:*cpe:2.3:o:juniper:junos:23.2:r1-s1:*:*:*:*:*:*cpe:2.3:o:juniper:junos:23.2:r1-s2:*:*:*:*:*:*- +25 more
Affected products
| Product | Versions |
|---|---|
| Juniper Networks · Junos OS | affected 0 < 21.4R3-S12 ; affected 22.2 < 22.2* ; affected 22.4 < 22.4R3-S8 ; affected 23.2 < 23.2R2-S5 ; affected 23.4 < 23.4R2-S5 ; affected 24.2 < 24.2R2-S3 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |