Cisco IOS XR Software up to 26.2.101 access control

Summaryinfo

A vulnerability identified as very critical has been detected in Cisco IOS XR Software. The affected element is an unknown function. This manipulation causes access control. The identification of this vulnerability is CVE-2026-20279. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in Cisco IOS XR Software. It has been declared as very critical. Affected by this vulnerability is some unknown functionality. The manipulation with an unknown input leads to a access control vulnerability. The CWE definition for the vulnerability is CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XR Software engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20279 are related to improper access control issues that are grouped under the Common Weakness Enumeration (CWE) CWE-284.

It is possible to read the advisory at sec.cloudapps.cisco.com. This vulnerability is known as CVE-2026-20279 since 10/08/2025. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/02/2026). The attack technique deployed by this issue is T1068 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

• Router Operating System

Vendor

• Cisco

Name

• IOS XR Software

Version

• 6.5.25
• 6.5.26
• 6.5.28
• 6.5.29
• 6.5.31
• 6.5.32
• 6.5.33
• 6.5.35
• 6.5.90
• 6.5.351
• 6.5.352
• 6.5.353
• 6.7.1
• 6.7.2
• 6.7.3
• 6.7.4
• 6.7.35
• 6.8.1
• 6.8.2
• 6.9.1
• 6.9.2
• 7.0.0
• 7.0.1
• 7.0.2
• 7.0.11
• 7.0.12
• 7.0.14
• 7.0.90
• 7.1.1
• 7.1.2
• 7.1.3
• 7.1.15
• 7.1.25
• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.12
• 7.3.1
• 7.3.2
• 7.3.3
• 7.3.4
• 7.3.5
• 7.3.6
• 7.3.15
• 7.3.16
• 7.3.27
• 7.4.1
• 7.4.2
• 7.4.15
• 7.4.16
• 7.5.1
• 7.5.2
• 7.5.3
• 7.5.4
• 7.5.5
• 7.5.12
• 7.5.52
• 7.6.1
• 7.6.2
• 7.6.3
• 7.6.15
• 7.7.1
• 7.7.2
• 7.7.21
• 7.8.1
• 7.8.2
• 7.8.12
• 7.8.22
• 7.8.23
• 7.9.1
• 7.9.2
• 7.9.21
• 7.10.1
• 7.10.2
• 7.11.1
• 7.11.2
• 7.11.21
• 24.1.1
• 24.1.2
• 24.2.1
• 24.2.2
• 24.2.11
• 24.2.20
• 24.2.21
• 24.3.1
• 24.3.2
• 24.3.20
• 24.3.30
• 24.4.1
• 24.4.2
• 24.4.10
• 24.4.15
• 24.4.30
• 25.1.1
• 25.1.2
• 25.1.30
• 25.2.1
• 25.2.2
• 25.2.15
• 25.2.30
• 25.3.1
• 25.3.15
• 25.4.1
• 25.4.2
• 25.4.30
• 25.4.201
• 26.1.1
• 26.1.2
• 26.2.1
• 26.2.100
• 26.2.101

License

• commercial

Website

• Vendor: https://www.cisco.com/

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