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Juniper published security advisories for two separate flaws affecting its management and telemetry products. In Junos Space, the ilpFilter field on nLegacy.jsp is vulnerable to reflected cross-site scripting tracked as CVE-2026-21904, exposing users to client-side script injection if they interact with a crafted request or link.
Juniper also disclosed a shell escape vulnerability in JSI Virtual Lightweight Collector that can allow privilege escalation to root, tracked as CVE-2026-21915. The advisories indicate that organizations using either product should review affected versions and apply Juniper’s recommended updates or mitigations to reduce the risk of administrative compromise and unauthorized code execution on impacted systems.
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Juniper published a security bulletin for CVE-2026-21919, describing a denial-of-service condition where a high frequency of connecting and disconnecting NETCONF sessions can cause management unavailability in Junos OS and Junos OS Evolved.
Juniper published a security bulletin for CVE-2026-21916, describing a privilege escalation flaw in Junos OS that could allow a low-privileged user to escalate privileges and log in as root.
Juniper published a security bulletin for CVE-2026-21915, describing a shell escape vulnerability in JSI Virtual Lightweight Collector that allows privilege escalation to root.
Juniper published a security bulletin for CVE-2026-21904, describing a reflected cross-site scripting issue in the ilpFilter field on nLegacy.jsp in Junos Space.
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Juniper disclosed two security vulnerabilities affecting **Junos OS** and **Junos OS Evolved**, including a flaw in **EX Series** and **QFX Series** switches where applying the same egress filter to both an IRB and a physical interface can cause one of the filters not to be enforced. The issue, tracked as **`CVE-2026-33773`**, could undermine intended network policy enforcement by leaving traffic insufficiently filtered on affected deployments. Juniper also published an advisory for **`CVE-2026-33793`**, warning that when an unsigned Python op script configuration is present, a local low-privileged user may be able to compromise the system. The vulnerability affects Junos platforms that permit that configuration state and creates a path for local privilege escalation or broader device compromise, prompting administrators to review exposed systems and apply vendor fixes or mitigations from Juniper's security bulletins.
Apr 9, 2026
Juniper Networks has released a comprehensive set of security patches addressing nearly 220 vulnerabilities across its Junos OS, Junos Space, and Security Director products, with a particular focus on nine critical flaws in Junos Space. Among the most severe issues is CVE-2025-59978, a cross-site scripting (XSS) vulnerability in Junos Space that allows attackers to inject malicious scripts into web pages, which are then executed with administrative privileges when viewed by other users. This could enable attackers to gain full control of the system, manipulate configurations, or exfiltrate sensitive data. Another critical flaw, CVE-2025-59974, affects Junos Space Security Director and also involves persistent XSS, enabling attackers to store and execute malicious scripts in the context of other users’ browsers. CVE-2025-59975 describes an uncontrolled resource consumption vulnerability in the HTTP daemon of Junos Space, where an attacker can flood the device with API calls, exhausting system resources and causing a denial of service that blocks both WebUI and CLI management access until a manual reboot is performed. CVE-2025-59968 highlights a missing authorization vulnerability in Junos Space Security Director, allowing unauthenticated attackers to read or modify metadata via the web interface, potentially resulting in managed SRX Series devices permitting unauthorized network traffic and bypassing security policies. Additionally, CVE-2025-11198 in Security Director Policy Enforcer exposes an unrestricted API that could let unauthenticated attackers upload and deploy malicious vSRX images to VMware NSX servers, provided a trusted user initiates deployment, thereby compromising the integrity of virtualized network security appliances. The vulnerabilities affect various versions of Junos Space and Security Director, with patches provided in Junos Space 24.1R4 Patch V1 and other specified updates. Juniper has stated that, as of the time of disclosure, there is no evidence of these vulnerabilities being exploited in the wild. The company strongly recommends that all users apply the latest patches to mitigate the risk of exploitation. The technical nature of these flaws, particularly those affecting administrative and management interfaces, underscores the potential for significant impact, including unauthorized access, denial of service, and compromise of network security controls. The breadth of the vulnerabilities, ranging from XSS to missing authorization and resource exhaustion, highlights the importance of comprehensive patch management and regular security reviews for organizations relying on Juniper’s network management solutions. The patches address not only the critical vulnerabilities but also a wide array of other issues, reflecting Juniper’s ongoing efforts to enhance the security posture of its products. Organizations are urged to review the affected product versions and ensure timely deployment of the recommended updates. Failure to patch could leave critical network infrastructure exposed to remote exploitation, data breaches, and operational disruptions. The coordinated disclosure and patch release demonstrate the importance of vendor transparency and proactive security practices in the face of evolving threats. Security teams should also consider reviewing access controls and monitoring for unusual activity on management interfaces as an additional precaution. The vulnerabilities serve as a reminder of the risks inherent in complex network management platforms and the necessity of maintaining up-to-date defenses.
Jun 29, 2026
Juniper disclosed two security vulnerabilities affecting **Junos OS** and **Junos OS Evolved**, including a local privilege-escalation flaw tracked as **`CVE-2026-21916`** that allows a low-privileged user to escalate privileges and log in as **`root`**. The issue creates a path for attackers who already have limited access to gain full administrative control over affected devices, increasing the risk of device takeover and unauthorized configuration changes. Juniper also published an advisory for **`CVE-2026-21919`**, a denial-of-service condition in **Junos OS** and **Junos OS Evolved** where a high frequency of connecting and disconnecting **NETCONF** sessions can cause management-plane unavailability. The flaw can disrupt administrative access and network operations by making device management unavailable, compounding the impact of the privilege-escalation issue for organizations running affected Juniper infrastructure.
Apr 9, 2026