CVE-2023-36835
Junos OS: QFX10000 Series: All traffic will be dropped after a specific valid IP packet has been received which needs to be routed over a VXLAN tunnel
An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on QFX10000 Series allows a network based attacker to cause a Denial of Service (DoS).
If a specific valid IP packet is received and that packet needs to be routed over a VXLAN tunnel, this will result in a PFE wedge condition due to which traffic gets impacted. As this is not a crash and restart scenario, this condition will persist until the system is rebooted to recover.
This issue affects Juniper Networks Junos OS on QFX10000: 20.3 version 20.3R1 and later versions; 20.4 versions prior to 20.4R3-S5; 21.1 versions prior to 21.1R3-S5; 21.2 versions prior to 21.2R3-S5; 21.3 versions prior to 21.3R3-S4; 21.4 versions prior to 21.4R3-S1; 22.1 versions prior to 22.1R3; 22.2 versions prior to 22.2R2; 22.3 versions prior to 22.3R1-S2, 22.3R2.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Junos OS: QFX10000 Series: All traffic will be dropped after a specific valid IP packet has been received which needs to be routed over a VXLAN tunnel
An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on QFX10000 Series allows a network based attacker to cause a Denial of Service (DoS).
If a specific valid IP packet is received and that packet needs to be routed over a VXLAN tunnel, this will result in a PFE wedge condition due to which traffic gets impacted. As this is not a crash and restart scenario, this condition will persist until the system is rebooted to recover.
This issue affects Juniper Networks Junos OS on QFX10000: 20.3 version 20.3R1 and later versions; 20.4 versions prior to 20.4R3-S5; 21.1 versions prior to 21.1R3-S5; 21.2 versions prior to 21.2R3-S5; 21.3 versions prior to 21.3R3-S4; 21.4 versions prior to 21.4R3-S1; 22.1 versions prior to 22.1R3; 22.2 versions prior to 22.2R2; 22.3 versions prior to 22.3R1-S2, 22.3R2.
- Record
CVE-2023-36835- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-754
- Updated
- 2026-11-02
EUVDEUVD-2023-40755
An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on QFX10000 Series allows a network based attacker to cause a Denial of Service (DoS).
If a specific valid IP packet is received and that packet needs to be routed over a VXLAN tunnel, this will result in a PFE wedge condition due to which traffic gets impacted. As this is not a crash and restart scenario, this condition will persist until the system is rebooted to recover.
This issue affects Juniper Networks Junos OS on QFX10000: 20.3 version 20.3R1 and later versions; 20.4 versions prior to 20.4R3-S5; 21.1 versions prior to 21.1R3-S5; 21.2 versions prior to 21.2R3-S5; 21.3 versions prior to 21.3R3-S4; 21.4 versions prior to 21.4R3-S1; 22.1 versions prior to 22.1R3; 22.2 versions prior to 22.2R2; 22.3 versions prior to 22.3R1-S2, 22.3R2.
- Record
EUVD-2023-40755- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-3xwf-x58p-42cm
An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding...
An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on QFX10000 Series allows a network based attacker to cause a Denial of Service (DoS).
If a specific valid IP packet is received and that packet needs to be routed over a VXLAN tunnel, this will result in a PFE wedge condition due to which traffic gets impacted. As this is not a crash and restart scenario, this condition will persist until the system is rebooted to recover.
This issue affects Juniper Networks Junos OS on QFX10000: 20.3 version 20.3R1 and later versions; 20.4 versions prior to 20.4R3-S5; 21.1 versions prior to 21.1R3-S5; 21.2 versions prior to 21.2R3-S5; 21.3 versions prior to 21.3R3-S4; 21.4 versions prior to 21.4R3-S1; 22.1 versions prior to 22.1R3; 22.2 versions prior to 22.2R2; 22.3 versions prior to 22.3R1-S2, 22.3R2.
- Record
GHSA-3xwf-x58p-42cm- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-754
- Updated
- 2026-11-02
NVD
An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on QFX10000 Series allows a network based attacker to cause a Denial of Service (DoS).
If a specific valid IP packet is received and that packet needs to be routed over a VXLAN tunnel, this will result in a PFE wedge condition due to which traffic gets impacted. As this is not a crash and restart scenario, this condition will persist until the system is rebooted to recover.
This issue affects Juniper Networks Junos OS on QFX10000: 20.3 version 20.3R1 and later versions; 20.4 versions prior to 20.4R3-S5; 21.1 versions prior to 21.1R3-S5; 21.2 versions prior to 21.2R3-S5; 21.3 versions prior to 21.3R3-S4; 21.4 versions prior to 21.4R3-S1; 22.1 versions prior to 22.1R3; 22.2 versions prior to 22.2R2; 22.3 versions prior to 22.3R1-S2, 22.3R2.
- Record
CVE-2023-36835- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-754
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2023-36835 is a high vulnerability (CVSS 7.5) in Juniper Junos, published July 14, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.64%, the 51st percentile. No source names a fixed version.