How severe is CVE-2020-26070?

CVE-2020-26070 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2020-26070 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-26070?

CVE-2020-26070 affects Cisco Ios Xr. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-26070?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2020-26070 published?

CVE-2020-26070 was published on 2020-11-12 and last updated on 2026-06-17.

CVE-2020-26070

CVE-2020-26070 is a high-severity vulnerability in Cisco Ios Xr with a CVSS 3.x base score of 8.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-404.

Key facts

Severity: High (CVSS 3.x base score 8.6)
CVSS v2: 7.8
EPSS exploit prediction: 2% (77th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-404
Affected product: Cisco Ios Xr
Published: 2020-11-12
Last modified: 2026-06-17

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.

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 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-26070 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-26070?: CVE-2020-26070 affects Cisco Ios Xr. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-26070?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-26070 published?: CVE-2020-26070 was published on 2020-11-12 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-xr-cp-dos-ej8VB9QY

Affected products (1)

cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*

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