CVE-2026-20277: Protection Mechanism Failure in Cisco Cisco IOS XR Software
Description
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.
CVSS v3.1
Score 8.2high
Affected software
Cisco
Cisco IOS XR Software
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Cisco IOS XR Software contains multiple protection mechanism failure vulnerabilities grouped under CWE-693, identified during an internal security review. These issues are tracked under CVE-2026-20277 and affect numerous specific versions of the software. The vulnerability has a CVSS 3.1 base score of 8.2, reflecting a high severity with network-based attack vector and significant impact on availability. No vendor advisory or patch information is provided in the input data.
Potential Impact
The vulnerability allows an attacker to cause a high impact on the availability of affected Cisco IOS XR Software versions without requiring privileges or user interaction. There is no confidentiality impact, and the integrity impact is limited. The attack can be performed remotely over the network with low complexity.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Cisco has conducted an internal review and released software hardening updates, but no explicit patch or remediation details are provided in the input data. Users should monitor Cisco's official advisories for updates and apply any available fixes promptly.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- cisco
- Date Reserved
- 2025-10-08T11:59:15.403Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6a9850dcacd9273b4977c517
Added to database: 09/02/2026, 16:37:48 UTC
Last enriched: 09/22/2026, 03:19:37 UTC
Last updated: 10/17/2026, 18:48:17 UTC
Views: 80
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