CVE-2026-101980: Junos OS: Malformed Extended Echo requests cause a Routing Engine reboot when Extended Echo is enabled
An Integer Underflow vulnerability in the kernel of Juniper Networks Junos OS with Extended Echo configured allows an unauthenticated, network-based attacker to cause a denial of service by a kernel crash.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
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Junos OSto a version that resolves this vulnerability.Fixed in 23.2R2-S7.7 - Upgrade
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Junos OSto a version that resolves this vulnerability.Fixed in 23.4R2-S8.13 - Upgrade
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Junos OSto a version that resolves this vulnerability.Fixed in 24.2R2-S5.5 - Upgrade
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Junos OSto a version that resolves this vulnerability.Fixed in 24.4R2-S5 - Upgrade
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Junos OSto a version that resolves this vulnerability.Fixed in 25.2R2-S2 - Upgrade
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Junos OSto a version that resolves this vulnerability.Fixed in 25.4R1-S3 - Upgrade
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Junos OSto a version that resolves this vulnerability.Fixed in 25.4R2 - Upgrade
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Junos OSto a version that resolves this vulnerability.Fixed in 26.2R1-S2 - Upgrade
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Junos OSto a version that resolves this vulnerability.Fixed in 26.2R2 - Upgrade
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Junos OSto a version that resolves this vulnerability.Fixed in 26.4R1
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
Juniper Networks Junos OS systems are exposed when Extended Echo is configured. The attack can be performed over the network without authentication or user interaction.
What is the practical impact of successful exploitation?
A remote attacker can send malformed Extended Echo requests that trigger an integer underflow in the kernel, causing a kernel crash and Routing Engine reboot. This results in a denial of service.
Is an attacker required to have credentials or prior access?
No. The vulnerability is described as unauthenticated and network-based, with no privileges or user interaction required.