Which versions of Junos Os Evolved are affected by CVE-2025-21599?

CVE-2025-21599 presents significant security risk rated CVSS 8.7. Successful exploitation could significantly impact the confidentiality, integrity, or availability of affected systems.

How to fix or mitigate CVE-2025-21599?

Within 30 days: Identify all affected systems and apply vendor patches as part of regular patch cycle. Monitor vendor channels for patch availability.

Junos Os Evolved CVE-2025-21599

Q: What is the CVSS score of CVE-2025-21599?

CVE-2025-21599 has a CVSS 4.0 base score of 8.7 (High). CVSS vector: CVSS:4.0/AV:N/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. EPSS exploitation probability: 0.3%.

HIGH

Memory Leak (CWE-401)

2025-01-09 sirt@juniper.net

Juniper Denial Of Service Junos Os Evolved

8.7

CVSS 4.0 · NVD

Severity by source

NVD PRIMARY

8.7 HIGH

CVSS:4.0/AV:N/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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:4.0/AV:N/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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Lifecycle Timeline

Analysis Generated

Mar 28, 2026 - 18:02 vuln.today

CVE Published

Jan 09, 2025 - 17:15 nvd

HIGH 8.7

DescriptionCVE.org

Receipt of specifically malformed IPv6 packets, destined to the device, causes kernel memory to not be freed, resulting in memory exhaustion leading to a system crash and Denial of Service (DoS). Continuous receipt and processing of these packets will continue to exhaust kernel memory, creating a sustained Denial of Service (DoS) condition. This issue only affects systems configured with IPv6.

This issue affects Junos OS Evolved:

from 22.4-EVO before 22.4R3-S5-EVO,
from 23.2-EVO before 23.2R2-S2-EVO,
from 23.4-EVO before 23.4R2-S2-EVO,
from 24.2-EVO before 24.2R1-S2-EVO, 24.2R2-EVO.

This issue does not affect Juniper Networks Junos OS Evolved versions prior to 22.4R1-EVO.

AnalysisAI

A Missing Release of Memory after Effective Lifetime vulnerability in the Juniper Tunnel Driver (jtd) of Juniper Networks Junos OS Evolved allows an unauthenticated network-based attacker to cause. Rated high severity (CVSS 8.7), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Technical ContextAI

This vulnerability is classified as Memory Leak (CWE-401), which allows attackers to exhaust available memory leading to denial of service. A Missing Release of Memory after Effective Lifetime vulnerability in the Juniper Tunnel Driver (jtd) of Juniper Networks Junos OS Evolved allows an unauthenticated network-based attacker to cause Denial of Service. Receipt of specifically malformed IPv6 packets, destined to the device, causes kernel memory to not be freed, resulting in memory exhaustion leading to a system crash and Denial of Service (DoS). Continuous receipt and processing of these packets will continue to exhaust kernel memory, creating a sustained Denial of Service (DoS) condition. This issue only affects systems configured with IPv6.4-EVO before 22.4R3-S5-EVO, * from 23.2-EVO before 23.2R2-S2-EVO, * from 23.4-EVO before 23.4R2-S2-EVO, * from 24.2-EVO before 24.2R1-S2-EVO, 24.2R2-EVO. This issue does not affect Juniper Networks Junos OS Evolved versions prior to 22.4R1-EVO. Affected products include: Juniper Junos Os Evolved. Version information: before 22.4.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Ensure all allocated memory is properly freed. Use RAII patterns or garbage-collected languages.