CVE-2023-36835Network attack vector

Persistent traffic outage via VXLAN-routed packet

Published Jul 14, 2023 · Updated Nov 7, 2024

Improper condition handling in Junos OS on QFX10000 affected releases allows remote attackers to interrupt traffic via a routed VXLAN packet. The Packet Forwarding Engine mishandles a specific valid IP packet while routing it over a VXLAN tunnel and enters a wedge condition. The packet must traverse an affected QFX10000 VXLAN route; the resulting outage persists until the device is rebooted.

CVSS severity7.5
High
EPSS probability0.64%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper condition handling in Junos OS on QFX10000 affected releases allows remote attackers to interrupt traffic via a routed VXLAN packet. The Packet Forwarding Engine mishandles a specific valid IP packet while routing it over a VXLAN tunnel and enters a wedge condition. The packet must traverse an affected QFX10000 VXLAN route; the resulting outage persists until the device is rebooted.

The record

CVE
CVE-2023-36835
Published
Jul 14, 2023
Updated
Nov 7, 2024
Vendor
Juniper Networks
Product
Junos OS
Classifications
CWE-754, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 14, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 7, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=20.3 <20.3*
  2. Affected versionversion=20.3 <20.3* changes=[{"at":"20.3R1","status":"affected"}]
  3. Affected versionversion=20.4 <20.4R3-S5
  4. Affected versionversion=21.1 <21.1R3-S5
  5. Affected versionversion=21.2 <21.2R3-S5
  6. Affected versionversion=21.3 <21.3R3-S4
  7. Affected versionversion=21.4 <21.4R3-S1
  8. Affected versionversion=22.1 <22.1R3
  9. Affected versionversion=22.2 <22.2R2
  10. Affected versionversion=22.3 <22.3R1-S2
  11. Affected versionversion=22.3 <22.3R1-S2, 22.3R2
  12. Affected versionversion=22.3 <22.3R2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Juniper Networks · Junos OSversion=20.3 <20.3*; version=20.3 <20.3* changes=[{"at":"20.3R1","status":"affected"}]; version=20.4 <20.4R3-S5; version=21.1 <21.1R3-S5; version=21.2 <21.2R3-S5; version=21.3 <21.3R3-S4; version=21.4 <21.4R3-S1; version=22.1 <22.1R3; version=22.2 <22.2R2; version=22.3 <22.3R1-S2; version=22.3 <22.3R1-S2, 22.3R2; version=22.3 <22.3R2

Published CVSS scores

7.5Juniper Networks, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-754Improper Check for Unusual or Exceptional Conditions
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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