CVE-2025-21595
Junos OS and Junos OS Evolved: In an EVPN-VXLAN scenario specific ARP or NDP packets cause FPC to crash
A Missing Release of Memory after Effective Lifetime vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent, unauthenticated attacker to cause an FPC to crash, leading to Denial of Service (DoS).
On all Junos OS and Junos OS Evolved platforms, in an EVPN-VXLAN scenario, when specific ARP packets are received on an IPv4 network, or specific NDP packets are received on an IPv6 network, kernel heap memory leaks, which eventually leads to an FPC crash and restart.
This issue does not affect MX Series platforms. Heap size growth on FPC can be seen using below command.
user@host> show chassis fpc Temp CPU Utilization (%) CPU Utilization (%) Memory Utilization (%) Slot State (C) Total Interrupt 1min 5min 15min DRAM (MB) Heap Buffer 0 Online 45 3 0 2 2 2 32768 19 0 <<<<<<< Heap increase in all fPCs
This issue affects Junos OS:
- All versions before 21.2R3-S7,
- 21.4 versions before 21.4R3-S4,
- 22.2 versions before 22.2R3-S1,
- 22.3 versions before 22.3R3-S1,
- 22.4 versions before 22.4R2-S2, 22.4R3.
and Junos OS Evolved:
-
All versions before 21.2R3-S7-EVO,
-
21.4-EVO versions before 21.4R3-S4-EVO,
-
22.2-EVO versions before 22.2R3-S1-EVO,
-
22.3-EVO versions before 22.3R3-S1-EVO,
-
22.4-EVO versions before 22.4R3-EVO.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent 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 and Junos OS Evolved: In an EVPN-VXLAN scenario specific ARP or NDP packets cause FPC to crash
A Missing Release of Memory after Effective Lifetime vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent, unauthenticated attacker to cause an FPC to crash, leading to Denial of Service (DoS).
On all Junos OS and Junos OS Evolved platforms, in an EVPN-VXLAN scenario, when specific ARP packets are received on an IPv4 network, or specific NDP packets are received on an IPv6 network, kernel heap memory leaks, which eventually leads to an FPC crash and restart.
This issue does not affect MX Series platforms. Heap size growth on FPC can be seen using below command.
user@host> show chassis fpc Temp CPU Utilization (%) CPU Utilization (%) Memory Utilization (%) Slot State (C) Total Interrupt 1min 5min 15min DRAM (MB) Heap Buffer 0 Online 45 3 0 2 2 2 32768 19 0 <<<<<<< Heap increase in all fPCs
This issue affects Junos OS:
- All versions before 21.2R3-S7,
- 21.4 versions before 21.4R3-S4,
- 22.2 versions before 22.2R3-S1,
- 22.3 versions before 22.3R3-S1,
- 22.4 versions before 22.4R2-S2, 22.4R3.
and Junos OS Evolved:
-
All versions before 21.2R3-S7-EVO,
-
21.4-EVO versions before 21.4R3-S4-EVO,
-
22.2-EVO versions before 22.2R3-S1-EVO,
-
22.3-EVO versions before 22.3R3-S1-EVO,
-
22.4-EVO versions before 22.4R3-EVO.
- Record
CVE-2025-21595- CVSS 4.0
- 7.1 High
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 - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-401
- Updated
- 2026-11-02
EUVDEUVD-2025-10527
A Missing Release of Memory after Effective Lifetime vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent, unauthenticated attacker to cause an FPC to crash, leading to Denial of Service (DoS).
On all Junos OS and Junos OS Evolved platforms, in an EVPN-VXLAN scenario, when specific ARP packets are received on an IPv4 network, or specific NDP packets are received on an IPv6 network, kernel heap memory leaks, which eventually leads to an FPC crash and restart.
This issue does not affect MX Series platforms. Heap size growth on FPC can be seen using below command.
user@host> show chassis fpc Temp CPU Utilization (%) CPU Utilization (%) Memory Utilization (%) Slot State (C) Total Interrupt 1min 5min 15min DRAM (MB) Heap Buffer 0 Online 45 3 0 2 2 2 32768 19 0 <<<<<<< Heap increase in all fPCs
This issue affects Junos OS:
- All versions before 21.2R3-S7,
- 21.4 versions before 21.4R3-S4,
- 22.2 versions before 22.2R3-S1,
- 22.3 versions before 22.3R3-S1,
- 22.4 versions before 22.4R2-S2, 22.4R3.
and Junos OS Evolved:
-
All versions before 21.2R3-S7-EVO,
-
21.4-EVO versions before 21.4R3-S4-EVO,
-
22.2-EVO versions before 22.2R3-S1-EVO,
-
22.3-EVO versions before 22.3R3-S1-EVO,
-
22.4-EVO versions before 22.4R3-EVO.
- Record
EUVD-2025-10527- CVSS 4.0
- 7.1 High
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-7fvw-hrgg-4cr6
A Missing Release of Memory after Effective Lifetime vulnerability in the Packet Forwarding...
A Missing Release of Memory after Effective Lifetime vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent, unauthenticated attacker to cause an FPC to crash, leading to Denial of Service (DoS).
On all Junos OS and Junos OS Evolved platforms, in an EVPN-VXLAN scenario, when specific ARP packets are received on an IPv4 network, or specific NDP packets are received on an IPv6 network, kernel heap memory leaks, which eventually leads to an FPC crash and restart.
This issue does not affect MX Series platforms. Heap size growth on FPC can be seen using below command.
user@host> show chassis fpc Temp CPU Utilization (%) CPU Utilization (%) Memory Utilization (%) Slot State (C) Total Interrupt 1min 5min 15min DRAM (MB) Heap Buffer 0 Online 45 3 0 2 2 2 32768 19 0 <<<<<<< Heap increase in all fPCs
This issue affects Junos OS:
- All versions before 21.2R3-S7,
- 21.4 versions before 21.4R3-S4,
- 22.2 versions before 22.2R3-S1,
- 22.3 versions before 22.3R3-S1,
- 22.4 versions before 22.4R2-S2, 22.4R3.
and Junos OS Evolved:
-
All versions before 21.2R3-S7-EVO,
-
21.4-EVO versions before 21.4R3-S4-EVO,
-
22.2-EVO versions before 22.2R3-S1-EVO,
-
22.3-EVO versions before 22.3R3-S1-EVO,
-
22.4-EVO versions before 22.4R3-EVO.
- Record
GHSA-7fvw-hrgg-4cr6- CVSS 4.0
- 7.1 High
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:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-401
- Updated
- 2026-11-02
NVD
A Missing Release of Memory after Effective Lifetime vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent, unauthenticated attacker to cause an FPC to crash, leading to Denial of Service (DoS).
On all Junos OS and Junos OS Evolved platforms, in an EVPN-VXLAN scenario, when specific ARP packets are received on an IPv4 network, or specific NDP packets are received on an IPv6 network, kernel heap memory leaks, which eventually leads to an FPC crash and restart.
This issue does not affect MX Series platforms. Heap size growth on FPC can be seen using below command.
user@host> show chassis fpc Temp CPU Utilization (%) CPU Utilization (%) Memory Utilization (%) Slot State (C) Total Interrupt 1min 5min 15min DRAM (MB) Heap Buffer 0 Online 45 3 0 2 2 2 32768 19 0 <<<<<<< Heap increase in all fPCs
This issue affects Junos OS:
- All versions before 21.2R3-S7,
- 21.4 versions before 21.4R3-S4,
- 22.2 versions before 22.2R3-S1,
- 22.3 versions before 22.3R3-S1,
- 22.4 versions before 22.4R2-S2, 22.4R3.
and Junos OS Evolved:
-
All versions before 21.2R3-S7-EVO,
-
21.4-EVO versions before 21.4R3-S4-EVO,
-
22.2-EVO versions before 22.2R3-S1-EVO,
-
22.3-EVO versions before 22.3R3-S1-EVO,
-
22.4-EVO versions before 22.4R3-EVO.
- Record
CVE-2025-21595- CVSS 4.0
- 7.1 High
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:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-401
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-21595 is a high vulnerability (CVSS 7.1) in Juniper Junos, published April 9, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.26%, the 18th percentile. No source names a fixed version.