Is CVE-2021-0266 actively exploited?

No active exploitation of CVE-2021-0266 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-0266 be exploited remotely?

Yes. CVE-2021-0266 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-0266?

CVE-2021-0266 has a CVSS score of 9.8 (CRITICAL).

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CRITICAL

CVE-2021-0266

CWE-321Published: April 22, 2021· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

The use of multiple hard-coded cryptographic keys in cSRX Series software in Juniper Networks Junos OS allows an attacker to take control of any instance of a cSRX deployment through device management services. This issue affects: Juniper Networks Junos OS on cSRX Series: All versions prior to 20.2R3; 20.3 versions prior to 20.3R2; 20.4 versions prior to 20.4R2.

NVD Source

Technical Analysis

CVE-2021-0266 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.