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: ghsa, secondary
Trending — 3 sources updated this weekElevated
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
49(Track)
EG Risk 49/100SSVC: 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%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
18%
EPSS %ILE
97%
KEV
Not listed

Published

February 25, 2026

Last Modified

June 17, 2026

Advisory Details (3)

Auto-updated Jul 27, 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 3× in last 7d / 3× 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. 2026-07-27 14:13 UTCEPSS rescore
  2. 2026-07-27 14:06 UTCEG score recompute
  3. 2026-07-27 14:05 UTCGHSA enrichment

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 3.2% 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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