CVE-2025-21599: juniper networks junos os evolved
Vulnerability summary
CVE-2025-21599 is a high (CVSS 8.7) vulnerability in juniper networks junos os evolved. EPSS estimates a 0.60% chance of exploitation in the next 30 days, higher than 47.9% of scored vulnerabilities.
Timeline
- 09-01-2025PublishedVulnerability first disclosed.
- 09-01-2025Last modifiedVulnerability information updated.
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 metrics
4 scores · 2 sources · 2 versions- NVDNIST8.7HighCVSS: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
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.60%
Chance of exploitation in the next 30 days
Percentile
48%
Versus all other CVEs
30-day change
0.00 pp
From 0.61% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Juniper1 product
- junos_os_evolved22.4 | 22.4:r1 | 22.4:r1-s1 | 22.4:r1-s2 | 22.4:r2 | 22.4:r2-s1 | 22.4:r2-s2 | 22.4:r3 | 22.4:r3-s1 | 22.4:r3-s2 | 22.4:r3-s3 | 22.4:r3-s4 | 23.2 | 23.2:r1 | 23.2:r1-s1 | 23.2:r1-s2 | 23.2:r2 | 23.2:r2-s1 | 23.4 | 23.4:r1 | 23.4:r1-s1 | 23.4:r1-s2 | 23.4:r2 | 23.4:r2-s1 | 24.2 | 24.2:r1 | 24.2:r2
Juniper networks1 product
- junos os evolved≥ 22.4-EVO, < 22.4R3-S5-EVO | ≥ 23.2-EVO, < 23.2R2-S2-EVO | ≥ 23.4-EVO, < 23.4R2-S2-EVO | ≥ 24.2-EVO, < 24.2R1-S2-EVO, 24.2R2-EVO
2 vendors · 2 products
References
1 links- supportportal.juniper.net/JSA92869Vendor Advisory