CVE-2025-52952
Junos OS: MX Series with MPC-BUILTIN, MPC 1 through MPC 9: Receipt and processing of a malformed packet causes one or more FPCs to crash
An Out-of-bounds Write vulnerability in the connectivity fault management (CFM) daemon of Juniper Networks Junos OS on MX Series with MPC-BUILTIN, MPC1 through MPC9 line cards allows an unauthenticated adjacent attacker to send a malformed packet to the device, leading to an FPC crash and restart, resulting in a Denial of Service (DoS).
Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition.
This issue affects Juniper Networks: Junos OS:
- All versions before 22.2R3-S1,
- from 22.4 before 22.4R2.
This feature is not enabled by default.
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: MX Series with MPC-BUILTIN, MPC 1 through MPC 9: Receipt and processing of a malformed packet causes one or more FPCs to crash
An Out-of-bounds Write vulnerability in the connectivity fault management (CFM) daemon of Juniper Networks Junos OS on MX Series with MPC-BUILTIN, MPC1 through MPC9 line cards allows an unauthenticated adjacent attacker to send a malformed packet to the device, leading to an FPC crash and restart, resulting in a Denial of Service (DoS).
Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition.
This issue affects Juniper Networks: Junos OS:
- All versions before 22.2R3-S1,
- from 22.4 before 22.4R2.
This feature is not enabled by default.
- Record
CVE-2025-52952- 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/AU:Y/R:A/V:C/RE:M/U:Green - 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-787
- Updated
- 2026-11-02
EUVDEUVD-2025-21157
An Out-of-bounds Write vulnerability in the connectivity fault management (CFM) daemon of Juniper Networks Junos OS on MX Series with MPC-BUILTIN, MPC1 through MPC9 line cards allows an unauthenticated adjacent attacker to send a malformed packet to the device, leading to an FPC crash and restart, resulting in a Denial of Service (DoS).
Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition.
This issue affects Juniper Networks: Junos OS:
- All versions before 22.2R3-S1,
- from 22.4 before 22.4R2.
This feature is not enabled by default.
- Record
EUVD-2025-21157- 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/AU:Y/R:A/V:C/RE:M/U:Green - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-pwqr-fp7x-9xcp
An Out-of-bounds Write vulnerability in the connectivity fault management (CFM) daemon of Juniper...
An Out-of-bounds Write vulnerability in the connectivity fault management (CFM) daemon of Juniper Networks Junos OS on MX Series with MPC-BUILTIN, MPC1 through MPC9 line cards allows an unauthenticated adjacent attacker to send a malformed packet to the device, leading to an FPC crash and restart, resulting in a Denial of Service (DoS).
Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition.
This issue affects Juniper Networks: Junos OS:
- All versions before 22.2R3-S1,
- from 22.4 before 22.4R2.
This feature is not enabled by default.
- Record
GHSA-pwqr-fp7x-9xcp- 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:Y/R:A/V:C/RE:M/U:Green - 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-787
- Updated
- 2026-11-02
NVD
An Out-of-bounds Write vulnerability in the connectivity fault management (CFM) daemon of Juniper Networks Junos OS on MX Series with MPC-BUILTIN, MPC1 through MPC9 line cards allows an unauthenticated adjacent attacker to send a malformed packet to the device, leading to an FPC crash and restart, resulting in a Denial of Service (DoS).
Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition.
This issue affects Juniper Networks: Junos OS:
- All versions before 22.2R3-S1,
- from 22.4 before 22.4R2.
This feature is not enabled by default.
- Record
CVE-2025-52952- 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:Y/R:A/V:C/RE:M/U:Green - 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-787
- 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-2025-52952 is a high vulnerability (CVSS 7.1) in Juniper Junos, published July 11, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.31%, the 24th percentile. No source names a fixed version.