CVE-2026-21902

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-02-25. a secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Elevated
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 18%CVSS: 9.8Exploit: Elevated riskExposed: 0

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

An Incorrect Permission Assignment for Critical Resource vulnerability in the On-Box Anomaly detection framework of Juniper Networks Junos OS Evolved on PTX Series allows an unauthenticated, network-based attacker to execute code as root.

The On-Box Anomaly detection framework should only be reachable by other internal processes over the internal routing instance, but not over an externally exposed port. With the ability to access and manipulate the service to execute code as root a remote attacker can take complete control of the device. Please note that this service is enabled by default as no specific configuration is required.

This issue affects Junos OS Evolved on PTX Series:

* 25.4 versions before 25.4R1-S1-EVO, 25.4R2-EVO.

This issue does not affect Junos OS Evolved versions before 25.4R1-EVO.

This issue does not affect Junos OS.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
65(Track*)
EG Risk 65/100SSVC: Track*

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity98% × 45%
Exploitation40% × 40%
Automatability30% × 15%
Action: Watch closely — could escalate to Attend.
EPSS PROB
18%
EPSS %ILE
97%
KEV
Not listed

Published

February 25, 2026

Last Modified

June 17, 2026

Advisory Details (3)

Auto-updated Sep 14, 2026
No patch confirmed yet.
generic

watchTowr-vs-JunosEvolved-CVE-2026-21902/watchTowr-vs-JunosEvolved-CVE-2026-21902.py at main · watchtowrlabs/watchTowr-vs-JunosEvolved-CVE-2026-21902 · GitHub

https://github.com/watchtowrlabs/watchTowr-vs-JunosEvolved-CVE-2026-21902/blob/main/watchTowr-vs-JunosEvolved-CVE-2026-21902.py
generic

CEC Juniper Community

https://supportportal.juniper.net/JSA107128
generic

CEC Juniper Community

https://kb.juniper.net/JSA107128

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 4× in last 7d / 23× 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.

  1. 2026-09-18 19:27 UTCEPSS rescore
  2. 2026-09-16 14:07 UTCEPSS rescore
  3. 2026-09-16 05:15 UTCEPSS rescore
  4. 2026-09-13 16:47 UTCEPSS rescore
  5. 2026-09-12 15:01 UTCEPSS rescore
  6. 2026-09-11 14:52 UTCEPSS rescore
  7. 2026-09-10 09:34 UTCEPSS rescore
  8. 2026-09-08 22:00 UTCEPSS rescore
  9. 2026-09-07 16:01 UTCEPSS rescore
  10. 2026-09-06 13:47 UTCEPSS rescore
  11. 2026-09-06 13:47 UTCEPSS rescore
  12. 2026-09-04 05:06 UTCEPSS rescore
  13. 2026-09-02 14:11 UTCEPSS rescore
  14. 2026-09-01 13:53 UTCEPSS rescore
  15. 2026-09-01 04:39 UTCEPSS rescore
  16. 2026-08-30 19:17 UTCEPSS rescore
  17. 2026-08-30 01:22 UTCEPSS rescore
  18. 2026-08-28 21:41 UTCEPSS rescore
  19. 2026-08-27 14:25 UTCEPSS rescore
  20. 2026-08-26 14:46 UTCEPSS rescore
  21. 2026-08-25 13:48 UTCEPSS rescore
  22. 2026-08-23 00:19 UTCEPSS rescore
  23. 2026-08-21 23:49 UTCEPSS rescore
  24. 2026-08-20 22:55 UTCEPSS rescore
  25. 2026-08-19 17:03 UTCEPSS rescore
Show 48 more
  1. 2026-08-18 13:48 UTCEPSS rescore
  2. 2026-08-16 14:56 UTCEPSS rescore
  3. 2026-08-16 02:14 UTCEPSS rescore
  4. 2026-08-15 01:30 UTCEPSS rescore
  5. 2026-08-15 01:29 UTCGHSA enrichment
  6. 2026-08-14 21:12 UTCGHSA enrichment
  7. 2026-08-14 13:13 UTCGHSA enrichment
  8. 2026-08-14 09:00 UTCEG score recompute
  9. 2026-08-14 09:00 UTCGHSA enrichment
  10. 2026-08-13 22:00 UTCEPSS rescore
  11. 2026-08-13 01:00 UTCEG score recompute
  12. 2026-08-13 01:00 UTCGHSA enrichment
  13. 2026-08-12 13:50 UTCEPSS rescore
  14. 2026-08-11 23:56 UTCEG score recompute
  15. 2026-08-11 23:56 UTCGHSA enrichment
  16. 2026-08-11 13:42 UTCEPSS rescore
  17. 2026-08-11 06:21 UTCEG score recompute
  18. 2026-08-11 06:21 UTCGHSA enrichment
  19. 2026-08-11 00:00 UTCEPSS rescore
  20. 2026-08-10 13:15 UTCGHSA enrichment
  21. 2026-08-10 08:47 UTCGHSA enrichment
  22. 2026-08-10 02:32 UTCGHSA enrichment
  23. 2026-08-09 22:18 UTCGHSA enrichment
  24. 2026-08-09 18:06 UTCGHSA enrichment
  25. 2026-08-09 13:49 UTCGHSA enrichment
  26. 2026-08-09 08:38 UTCEG score recompute
  27. 2026-08-09 08:38 UTCGHSA enrichment
  28. 2026-08-08 16:37 UTCEPSS rescore
  29. 2026-08-08 09:21 UTCGHSA enrichment
  30. 2026-08-08 05:08 UTCGHSA enrichment
  31. 2026-08-08 00:55 UTCGHSA enrichment
  32. 2026-08-07 20:42 UTCEG score recompute
  33. 2026-08-07 20:42 UTCGHSA enrichment
  34. 2026-08-06 13:46 UTCEPSS rescore
  35. 2026-08-06 07:13 UTCGHSA enrichment
  36. 2026-08-06 03:00 UTCEG score recompute
  37. 2026-08-06 03:00 UTCGHSA enrichment
  38. 2026-08-05 19:17 UTCEPSS rescore
  39. 2026-08-04 15:10 UTCEPSS rescore
  40. 2026-08-04 10:38 UTCEPSS rescore
  41. 2026-08-04 05:50 UTCGHSA enrichment
  42. 2026-08-02 23:46 UTCGHSA enrichment
  43. 2026-08-02 19:33 UTCEG score recompute
  44. 2026-08-02 19:33 UTCGHSA enrichment
  45. 2026-08-01 04:15 UTCEPSS rescore
  46. 2026-07-27 14:13 UTCEPSS rescore
  47. 2026-07-27 14:06 UTCEG score recompute
  48. 2026-07-27 14:05 UTCGHSA enrichment

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCwatchtowrlabs/watchTowr-vs-JunosEvolved-CVE-2026-21902
    First seen Feb 28, 2026
    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-21902?
CVE-2026-21902 is a critical vulnerability published on February 25, 2026. An Incorrect Permission Assignment for Critical Resource vulnerability in the On-Box Anomaly detection framework of Juniper Networks Junos OS Evolved on PTX Series allows an unauthenticated, network-based attacker to execute code as root. The On-Box Anomaly detection framework should only be…
When was CVE-2026-21902 disclosed?
CVE-2026-21902 was first published in the National Vulnerability Database on February 25, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-21902 actively exploited?
CVE-2026-21902 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 18% probability of exploitation in the next 30 days, which ranks it in the top 3.0% of all scored CVEs.
What is the CVSS score of CVE-2026-21902?
CVE-2026-21902 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-21902?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-21902, 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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