Juniper Junos OS 21.4 · Version Status
Juniper Junos OS 21.4 End of Life Date
Juniper Junos OS 21.4 end-of-life date, support status, and CVE risk. Data from endoflife.date and official vendor documentation.
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Juniper Junos OS 21.4 is past end of life. This version no longer receives security patches. 438 days past EOL — migrate to a supported version immediately.
EOL Date
Jun 20, 2025
438 days past EOL
Latest Release
21.4
Standard release
Release Date
Dec 20, 2021
Juniper Junos OS 21.4 series
Lifecycle detail
Juniper Junos OS 21.4 was released on December 20, 2021 and support ended on June 20, 2025 — a supported lifespan of 3 years and 6 months, in line with the 3 years and 6 months median for Juniper Junos OS releases. It has been without security patches for 1 year and 2 months. 3 newer Juniper Junos OS releases have shipped since.
Attack Surface
10/30 Medium tier
CISA KEV Exposure
20/20 Named in CISA KEV
Extended Support
0/10 Available
EOL Risk Score™ — proprietary methodology by endoflife.ai. Factors: EOL recency, attack surface breadth, CISA KEV catalog presence, extended support availability. Updated at every build.
Methodology → ·
View score card →
Extended Support
Extended Juniper Junos OS 21.4 support is available
Commercial vendors offer security patches beyond EOL. Compare your options.
Compare Options →
All Juniper Junos OS Versions
| Version | Latest | EOL Date | Status |
|---|
| 20.2 |
20.2 |
Dec 30, 2023 |
EOL |
| 20.3 |
20.3 |
Mar 29, 2023 |
EOL |
| 20.4 |
20.4 |
Jun 25, 2024 |
EOL |
| 21.1 |
21.1 |
Sep 25, 2023 |
EOL |
| 21.2 |
21.2 |
Dec 29, 2024 |
EOL |
| 21.3 |
21.3 |
Mar 23, 2024 |
EOL |
| → 21.4 |
21.4 |
Jun 20, 2025 |
EOL |
| 22.1 |
22.1 |
Sep 24, 2024 |
EOL |
What does Juniper Junos OS 21.4 end of life mean?
When Juniper Junos OS 21.4 reaches end of life, the maintainers stop issuing security patches for this version. CVEs discovered after the EOL date are publicly disclosed on the National Vulnerability Database with no patch available. Exploit code frequently appears on GitHub within days of disclosure.
The CVE blind spot: Most vulnerability scanners check for known CVEs but do not flag the ongoing accumulation of unpatched vulnerabilities in EOL software versions. Running Juniper Junos OS 21.4 past its EOL date creates a permanently growing attack surface that standard security tooling will not surface.
Migrate to Juniper Junos OS 26.2 or implement compensating controls — network segmentation, enhanced monitoring, restricted access — while migration is underway.
Frequently Asked Questions
When does Juniper Junos OS 21.4 reach end of life?
Juniper Junos OS 21.4 reached end of life on June 20, 2025. This version is no longer receiving security patches.
Is Juniper Junos OS 21.4 still supported?
No. Juniper Junos OS 21.4 reached end of life on June 20, 2025 and is no longer receiving security patches.
What should I upgrade to from Juniper Junos OS 21.4?
The recommended upgrade from Juniper Junos OS 21.4 is
Juniper Junos OS 26.2 — the latest actively supported version. Check the
Juniper Junos OS full timeline for all supported versions.
What are the security risks of running Juniper Junos OS 21.4 past EOL?
When Juniper Junos OS 21.4 reaches end of life, the maintainers stop issuing security patches. Any CVEs disclosed after the EOL date accumulate with no remediation path. Most vulnerability scanners do not flag this — it is the CVE blind spot. Organizations running EOL Juniper Junos OS should migrate immediately or implement compensating controls.