CVE-2025-21590

MEDIUMNVD 4.49.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2025-03-13), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 4.4 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, nvd
Trending — 4 sources updated this weekExploited in the wild
4.4
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS: 2%CVSS: 4.4Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

An Improper Isolation or Compartmentalization vulnerability in the kernel of Juniper Networks Junos OS allows a local attacker with high privileges to compromise the integrity of the device.

A local attacker with access to the shell is able to inject arbitrary code which can compromise an affected device. This issue is not exploitable from the Junos CLI. This issue affects Junos OS: 

* All versions before 21.2R3-S9, * 21.4 versions before 21.4R3-S10,  * 22.2 versions before 22.2R3-S6,  * 22.4 versions before 22.4R3-S6,  * 23.2 versions before 23.2R2-S3,  * 23.4 versions before 23.4R2-S4, * 24.2 versions before 24.2R1-S2, 24.2R2.

CVSS v3
4.4
EG Score
9.0(high)
EPSS
74.2%
KEV
⚠ Exploited

Published

March 12, 2025

Last Modified

October 24, 2025

Advisory Details (3)

Auto-updated Jun 14, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: cisa.
cisa Patch Available🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-21590
generic

CEC Juniper Community

https://supportportal.juniper.net/JSA93446
generic

Ghost in the Router: China-Nexus Espionage Actor UNC3886 Targets Juniper Routers | Google Cloud Blog

https://cloud.google.com/blog/topics/threat-intelligence/china-nexus-espionage-targets-juniper-routers

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 57× in last 7d / 226× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 403 total refreshes for this CVE.

  1. 2026-07-22 19:40 UTCCISA KEV update
  2. 2026-07-22 18:18 UTCEG score recompute
  3. 2026-07-22 18:18 UTCGHSA enrichment
  4. 2026-07-22 14:07 UTCEPSS rescore
  5. 2026-07-22 14:07 UTCEPSS rescore
  6. 2026-07-22 13:54 UTCGHSA enrichment
  7. 2026-07-22 09:31 UTCGHSA enrichment
  8. 2026-07-22 05:08 UTCGHSA enrichment
  9. 2026-07-22 00:44 UTCGHSA enrichment
  10. 2026-07-21 20:21 UTCGHSA enrichment
  11. 2026-07-21 15:57 UTCEG score recompute
  12. 2026-07-21 15:57 UTCGHSA enrichment
  13. 2026-07-21 15:24 UTCEPSS rescore
  14. 2026-07-21 14:37 UTCCISA KEV update
  15. 2026-07-21 11:33 UTCGHSA enrichment
  16. 2026-07-21 07:07 UTCGHSA enrichment
  17. 2026-07-21 02:42 UTCGHSA enrichment
  18. 2026-07-20 22:18 UTCGHSA enrichment
  19. 2026-07-20 17:55 UTCEG score recompute
  20. 2026-07-20 17:55 UTCGHSA enrichment
  21. 2026-07-20 17:07 UTCEPSS rescore
  22. 2026-07-20 13:32 UTCGHSA enrichment
  23. 2026-07-20 09:09 UTCGHSA enrichment
  24. 2026-07-20 04:45 UTCGHSA enrichment
  25. 2026-07-19 19:56 UTCGHSA enrichment
Show 75 more
  1. 2026-07-19 15:33 UTCEG score recompute
  2. 2026-07-19 15:33 UTCGHSA enrichment
  3. 2026-07-19 14:30 UTCEPSS rescore
  4. 2026-07-19 14:30 UTCEPSS rescore
  5. 2026-07-19 11:10 UTCGHSA enrichment
  6. 2026-07-19 06:47 UTCEG score recompute
  7. 2026-07-19 06:47 UTCGHSA enrichment
  8. 2026-07-19 02:28 UTCEPSS rescore
  9. 2026-07-19 02:28 UTCEPSS rescore
  10. 2026-07-19 02:23 UTCGHSA enrichment
  11. 2026-07-18 22:00 UTCGHSA enrichment
  12. 2026-07-18 17:37 UTCGHSA enrichment
  13. 2026-07-18 13:13 UTCEG score recompute
  14. 2026-07-18 13:13 UTCGHSA enrichment
  15. 2026-07-18 10:03 UTCEPSS rescore
  16. 2026-07-18 08:50 UTCGHSA enrichment
  17. 2026-07-18 04:27 UTCGHSA enrichment
  18. 2026-07-18 00:03 UTCGHSA enrichment
  19. 2026-07-17 19:40 UTCGHSA enrichment
  20. 2026-07-17 15:17 UTCGHSA enrichment
  21. 2026-07-17 10:53 UTCEG score recompute
  22. 2026-07-17 10:53 UTCGHSA enrichment
  23. 2026-07-17 06:30 UTCGHSA enrichment
  24. 2026-07-17 02:06 UTCGHSA enrichment
  25. 2026-07-16 21:42 UTCGHSA enrichment
  26. 2026-07-16 17:19 UTCGHSA enrichment
  27. 2026-07-16 17:04 UTCCISA KEV update
  28. 2026-07-16 17:02 UTCEPSS rescore
  29. 2026-07-16 12:55 UTCGHSA enrichment
  30. 2026-07-16 08:32 UTCGHSA enrichment
  31. 2026-07-16 04:09 UTCGHSA enrichment
  32. 2026-07-15 23:46 UTCGHSA enrichment
  33. 2026-07-15 19:23 UTCGHSA enrichment
  34. 2026-07-15 16:57 UTCEPSS rescore
  35. 2026-07-15 16:57 UTCEPSS rescore
  36. 2026-07-15 16:49 UTCCISA KEV update
  37. 2026-07-15 15:04 UTCCISA KEV update
  38. 2026-07-15 14:59 UTCGHSA enrichment
  39. 2026-07-15 10:35 UTCGHSA enrichment
  40. 2026-07-15 06:10 UTCGHSA enrichment
  41. 2026-07-15 01:59 UTCEPSS rescore
  42. 2026-07-15 01:47 UTCGHSA enrichment
  43. 2026-07-14 21:24 UTCGHSA enrichment
  44. 2026-07-14 18:05 UTCCISA KEV update
  45. 2026-07-14 17:01 UTCGHSA enrichment
  46. 2026-07-14 12:38 UTCGHSA enrichment
  47. 2026-07-14 08:14 UTCGHSA enrichment
  48. 2026-07-14 03:51 UTCGHSA enrichment
  49. 2026-07-13 23:28 UTCGHSA enrichment
  50. 2026-07-13 22:29 UTCEPSS rescore
  51. 2026-07-13 22:29 UTCEPSS rescore
  52. 2026-07-13 19:05 UTCGHSA enrichment
  53. 2026-07-13 17:07 UTCCISA KEV update
  54. 2026-07-13 14:42 UTCGHSA enrichment
  55. 2026-07-13 10:19 UTCGHSA enrichment
  56. 2026-07-13 05:56 UTCGHSA enrichment
  57. 2026-07-13 01:32 UTCGHSA enrichment
  58. 2026-07-12 21:09 UTCGHSA enrichment
  59. 2026-07-12 16:45 UTCGHSA enrichment
  60. 2026-07-12 12:22 UTCGHSA enrichment
  61. 2026-07-12 07:59 UTCGHSA enrichment
  62. 2026-07-12 05:46 UTCEPSS rescore
  63. 2026-07-12 05:46 UTCEPSS rescore
  64. 2026-07-12 03:35 UTCGHSA enrichment
  65. 2026-07-11 23:10 UTCGHSA enrichment
  66. 2026-07-11 18:46 UTCGHSA enrichment
  67. 2026-07-11 14:23 UTCGHSA enrichment
  68. 2026-07-11 10:00 UTCGHSA enrichment
  69. 2026-07-11 08:27 UTCEPSS rescore
  70. 2026-07-11 08:26 UTCEPSS rescore
  71. 2026-07-11 05:37 UTCGHSA enrichment
  72. 2026-07-11 01:13 UTCGHSA enrichment
  73. 2026-07-10 20:49 UTCGHSA enrichment
  74. 2026-07-10 17:52 UTCCISA KEV update
  75. 2026-07-10 16:26 UTCGHSA enrichment

Frequently asked(6)

What is CVE-2025-21590?
CVE-2025-21590 is a medium vulnerability published on March 12, 2025. An Improper Isolation or Compartmentalization vulnerability in the kernel of Juniper Networks Junos OS allows a local attacker with high privileges to compromise the integrity of the device. A local attacker with access to the shell is able to inject arbitrary code which can compromise an affected…
When was CVE-2025-21590 disclosed?
CVE-2025-21590 was first published in the National Vulnerability Database on March 12, 2025, with the most recent update on October 24, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-21590 actively exploited?
Yes. CISA added CVE-2025-21590 to the Known Exploited Vulnerabilities catalog on March 13, 2025, affecting Juniper Junos OS. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2025-21590?
CVE-2025-21590 has a CVSS v3 base score of 4.4 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
Which products are affected by CVE-2025-21590?
CVE-2025-21590 affects Juniper Junos OS. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2025-21590?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-21590, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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