CVE-2020-26070: A vulnerability in the ingress packet processing function of Cisco IOS XR Software for Cisco ASR 9000 Series Aggregation Services Routers could allow ...

Description

A vulnerability in the ingress packet processing function of Cisco IOS XR Software for Cisco ASR 9000 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper resource allocation when an affected device processes network traffic in software switching mode (punted). An attacker could exploit this vulnerability by sending specific streams of Layer 2 or Layer 3 protocol data units (PDUs) to an affected device. A successful exploit could cause the affected device to run out of buffer resources, which could make the device unable to process or forward traffic, resulting in a DoS condition. The device would need to be restarted to regain functionality.

Metrics

CVSS 3.1

8.6/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

EPSS Probability

1.88%

76.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Cisco	Ios Xr	< 6.7.2
Cisco	Ios Xr	>= 7.1.0, < 7.1.2

References

Timeline

Published: Nov 12, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-26070?

A vulnerability in the ingress packet processing function of Cisco IOS XR Software for Cisco ASR 9000 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper resource allocation when an affected device processes network traffic in software switching mode (punted). An attacker could exploit this vulnerability by sending specific streams of Layer 2 or Layer 3 protocol data units (PDUs) to an affected device. A successful exploit could cause the affected device to run out of buffer resources, which could make the device unable to process or forward traffic, resulting in a DoS condition. The device would need to be restarted to regain functionality.

How severe is CVE-2020-26070?

CVE-2020-26070 has a CVSS score of 8.6/10 (HIGH severity). The EPSS model estimates a 1.88% probability of exploitation in the next 30 days.

How do I fix CVE-2020-26070?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.