CVE-2025-21590

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.

Data as of 2 Nov 2026 · NVD, CISA KEV, EPSS

Defenders still triage vulnerabilities one CVE at a time, while increasingly automated attackers combine them at machine speed. Omenwave models the plausible pathways by which this CVE could be chained with others — surfacing them for research and awareness, with evidence for each step.

Kill-chain stage

IMPACT

Requires

PRIV access, LOCAL vector

Grants

PRIV access (terminal impact)

Capabilities

data tampering

Model confidence

high · CVSS 3.1

No plausible forward hops are modelled from this CVE in the current corpus (it may be a terminal impact, or an independent entry point rather than a continuation).