Cisco IOS XR Software up to 26.2.101 protection mechanism

Summaryinfo

A vulnerability was found in Cisco IOS XR Software. It has been rated as critical. This issue affects some unknown processing. The manipulation leads to protection mechanism. This vulnerability is uniquely identified as CVE-2026-20277. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability was found in Cisco IOS XR Software and classified as critical. This issue affects an unknown function. The manipulation with an unknown input leads to a protection mechanism vulnerability. Using CWE to declare the problem leads to CWE-693. The product does not use or incorrectly uses a protection mechanism that provides sufficient defense against directed attacks against the product. Impacted is 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-2026-20277 are related to protection mechanism failure issues that are grouped under the Common Weakness Enumeration (CWE) CWE-693.

The advisory is shared at sec.cloudapps.cisco.com. The identification of this vulnerability is CVE-2026-20277 since 10/08/2025. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/02/2026).

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

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

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Exploitinginfo

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Timelineinfo

Sourcesinfo

Entryinfo

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