CVE-2025-21599
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.60%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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. 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.
- CVSS 4.0
- 8.7 HIGHCVSS: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/M
- EPSS
- 0.60% probability · 49th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-401
- Affected
- juniper/junos os evolved
- Source
- sirt@juniper.net
EPSS 0.6% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://supportportal.juniper.net/JSA92869Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.