CVE-2025-21589

CVE-2025-21589 is a critical-severity vulnerability with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-288.

Key facts

Description

An Authentication Bypass Using an Alternate Path or Channel vulnerability in Juniper Networks Session Smart Router may allows a network-based attacker to bypass authentication and take administrative control of the device. This issue affects Session Smart Router:  * from 5.6.7 before 5.6.17,  * from 6.0 before 6.0.8 (affected from 6.0.8), * from 6.1 before 6.1.12-lts,  * from 6.2 before 6.2.8-lts,  * from 6.3 before 6.3.3-r2;  This issue affects Session Smart Conductor:  * from 5.6.7 before 5.6.17,  * from 6.0 before 6.0.8 (affected from 6.0.8), * from 6.1 before 6.1.12-lts,  * from 6.2 before 6.2.8-lts,  * from 6.3 before 6.3.3-r2;  This issue affects WAN Assurance Managed Routers:  * from 5.6.7 before 5.6.17,  * from 6.0 before 6.0.8 (affected from 6.0.8), * from 6.1 before 6.1.12-lts,  * from 6.2 before 6.2.8-lts,  * from 6.3 before 6.3.3-r2.

Frequently asked questions

What is CVE-2025-21589?
An Authentication Bypass Using an Alternate Path or Channel vulnerability in Juniper Networks Session Smart Router may allows a network-based attacker to bypass authentication and take administrative control of the device. This issue affects Session Smart Router:  * from 5.6.7 before 5.6.17,  * from 6.0 before 6.0.8 (affected from 6.0.8), * from 6.1 before 6.1.12-lts,  * from 6.2 before 6.2.8-lts,  * from 6.3 before 6.3.3-r2;  This issue affects Session Smart Conductor:  * from 5.6.7 before 5.6.17,  * from 6.0 before 6.0.8 (affected from 6.0.8), * from 6.1 before 6.1.12-lts,  * from 6.2 before 6.2.8-lts,  * from 6.3 before 6.3.3-r2;  This issue affects WAN Assurance Managed Routers:  * from 5.6.7 before 5.6.17,  * from 6.0 before 6.0.8 (affected from 6.0.8), * from 6.1 before 6.1.12-lts,  * from 6.2 before 6.2.8-lts,  * from 6.3 before 6.3.3-r2.
How severe is CVE-2025-21589?
CVE-2025-21589 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-21589 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-21589?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2025-21589 have an EU (EUVD) identifier?
Yes. CVE-2025-21589 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-206381.
When was CVE-2025-21589 published?
CVE-2025-21589 was published on 2026-01-27 and last updated on 2026-06-17.

References

Other CWE-288 vulnerabilities

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