Vulnerability Monitor

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CVE-2026-21906


An Improper Handling of Exceptional Conditions vulnerability in the packet forwarding engine (PFE) of Juniper Networks Junos OS on SRX Series allows an unauthenticated network-based attacker sending a specific ICMP packet through a GRE tunnel to cause the PFE to crash and restart. When PowerMode IPsec (PMI) and GRE performance acceleration are enabled and the device receives a specific ICMP packet, a crash occurs in the SRX PFE, resulting in traffic loss. PMI is enabled by default, and GRE performance acceleration can be enabled by running the configuration command shown below. PMI is a mode of operation that provides IPsec performance improvements using Vector Packet Processing. Note that PMI with GRE performance acceleration is only supported on specific SRX platforms. This issue affects Junos OS on the SRX Series: * all versions before 21.4R3-S12,  * from 22.4 before 22.4R3-S8,  * from 23.2 before 23.2R2-S5,  * from 23.4 before 23.4R2-S5,  * from 24.2 before 24.2R2-S3,  * from 24.4 before 24.4R2-S1,  * from 25.2 before 25.2R1-S1, 25.2R2.


Security Impact Summary

This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 7.5, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts and availability (service disruption) for affected systems. Impacting 18 products from juniper, from juniper, from juniper and 15 others, organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2026, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.


Published

2026-01-15T21:16:06.177

Last Modified

2026-01-23T19:40:34.157

Status

Analyzed

Source

[email protected]

Severity

CVSSv3.1: 7.5 (HIGH)

Weaknesses
  • Type: Primary
    CWE-755

Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Operating System juniper junos < 21.4 Yes
Operating System juniper junos 21.4 Yes
Operating System juniper junos 21.4 Yes
Operating System juniper junos 21.4 Yes
Operating System juniper junos 21.4 Yes
Operating System juniper junos 21.4 Yes
Operating System juniper junos 21.4 Yes
Operating System juniper junos 21.4 Yes
Operating System juniper junos 21.4 Yes
Operating System juniper junos 21.4 Yes
Operating System juniper junos 21.4 Yes
Operating System juniper junos 21.4 Yes
Operating System juniper junos 21.4 Yes
Operating System juniper junos 21.4 Yes
Operating System juniper junos 21.4 Yes
Operating System juniper junos 21.4 Yes
Operating System juniper junos 21.4 Yes
Operating System juniper junos 21.4 Yes
Operating System juniper junos 21.4 Yes
Operating System juniper junos 21.4 Yes
Operating System juniper junos 22.4 Yes
Operating System juniper junos 22.4 Yes
Operating System juniper junos 22.4 Yes
Operating System juniper junos 22.4 Yes
Operating System juniper junos 22.4 Yes
Operating System juniper junos 22.4 Yes
Operating System juniper junos 22.4 Yes
Operating System juniper junos 22.4 Yes
Operating System juniper junos 22.4 Yes
Operating System juniper junos 22.4 Yes
Operating System juniper junos 22.4 Yes
Operating System juniper junos 22.4 Yes
Operating System juniper junos 22.4 Yes
Operating System juniper junos 22.4 Yes
Operating System juniper junos 22.4 Yes
Operating System juniper junos 23.2 Yes
Operating System juniper junos 23.2 Yes
Operating System juniper junos 23.2 Yes
Operating System juniper junos 23.2 Yes
Operating System juniper junos 23.2 Yes
Operating System juniper junos 23.2 Yes
Operating System juniper junos 23.2 Yes
Operating System juniper junos 23.2 Yes
Operating System juniper junos 23.2 Yes
Operating System juniper junos 23.4 Yes
Operating System juniper junos 23.4 Yes
Operating System juniper junos 23.4 Yes
Operating System juniper junos 23.4 Yes
Operating System juniper junos 23.4 Yes
Operating System juniper junos 23.4 Yes
Operating System juniper junos 23.4 Yes
Operating System juniper junos 23.4 Yes
Operating System juniper junos 23.4 Yes
Operating System juniper junos 24.2 Yes
Operating System juniper junos 24.2 Yes
Operating System juniper junos 24.2 Yes
Operating System juniper junos 24.2 Yes
Operating System juniper junos 24.2 Yes
Operating System juniper junos 24.2 Yes
Operating System juniper junos 24.2 Yes
Operating System juniper junos 24.4 Yes
Operating System juniper junos 24.4 Yes
Operating System juniper junos 24.4 Yes
Operating System juniper junos 24.4 Yes
Operating System juniper junos 24.4 Yes
Operating System juniper junos 25.2 Yes
Operating System juniper junos 25.2 Yes
Operating System juniper junos 25.2 Yes
Hardware juniper srx1500 - No
Hardware juniper srx1600 - No
Hardware juniper srx2300 - No
Hardware juniper srx300 - No
Hardware juniper srx320 - No
Hardware juniper srx340 - No
Hardware juniper srx345 - No
Hardware juniper srx380 - No
Hardware juniper srx4100 - No
Hardware juniper srx4120 - No
Hardware juniper srx4200 - No
Hardware juniper srx4300 - No
Hardware juniper srx4600 - No
Hardware juniper srx4700 - No
Hardware juniper srx5400 - No
Hardware juniper srx5600 - No
Hardware juniper srx5800 - No

References

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For juniper's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.