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CVE-2026-20271— Cisco IOS XE Software Security Hardening Release

Quick assessment

Affected
Cisco Cisco IOS XE Software
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Cisco IOS XE Software是美国Cisco公司的一款管理网络设备的操作系统。 Cisco IOS XE Software 16.6.2版本至26.1.1a版本存在处理逻辑错误漏洞，该漏洞源于控制流管理不足，可能导致拒绝服务。

CVSS 8.6 · High EPSS 0.47% · P38

Possible ATT&CK Techniques 1 AI

T1190 · Exploit Public-Facing Application

Affected Version Matrix 268

VendorProduct Version RangeStatus
Cisco Cisco IOS XE Software 17.2.1a affected
16.12.1y affected
16.12.3s affected
16.7.1b affected
16.6.2 affected
16.6.5 affected
16.12.1w affected
16.9.1d affected
… +260 more rows
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I. Basic Information for CVE-2026-20271

Vulnerability Information
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Vulnerability Title
Cisco IOS XE Software Security Hardening Release
Source: CVE Program / CVE List V5
Vulnerability Description
As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XE Software engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20271 are related to insufficient control flow management issues that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-691.  
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
不充分的控制流管理
Source: CVE Program / CVE List V5
Vulnerability Title
Cisco IOS XE Software 处理逻辑错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Cisco IOS XE Software是美国Cisco公司的一款管理网络设备的操作系统。 Cisco IOS XE Software 16.6.2版本至26.1.1a版本存在处理逻辑错误漏洞，该漏洞源于控制流管理不足，可能导致拒绝服务。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Cisco Cisco IOS XE Software 17.2.1a -

II. Public POCs for CVE-2026-20271

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III. Intelligence Information for CVE-2026-20271

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Vendor Advisories for CVE-2026-20271 (1)

Same Patch Batch · Cisco · 2026-08-05 · 23 CVEs total

CVE-2026-20304 9.9 CRITICAL Cisco Catalyst SD-WAN Security Hardening Release - Access Control Vulnerabilities
CVE-2026-20303 9.9 CRITICAL Cisco Catalyst SD-WAN Security Hardening Release - Input Validation Vulnerabilities
CVE-2026-20272 9.8 CRITICAL Cisco IOS XE Software Security Hardening Release
CVE-2026-20310 9.1 CRITICAL Cisco SD-WAN Software Security Hardening Release - Improper Link Resolution Before File Ac
CVE-2026-20267 9.0 CRITICAL Cisco IOS XE Software Security Hardening Release
CVE-2026-20312 8.8 HIGH Cisco Catalyst SD-WAN Security Hardening Release - Information Disclosure Vulnerabilities
CVE-2026-20200 8.8 HIGH Cisco Integrated Management Controller Argument Injection and Remote Code Execution Vulner
CVE-2026-20263 8.6 HIGH Cisco IOS XE Software Blocks Extensible Exchange Protocol Denial of Service Vulnerability
CVE-2026-20268 8.6 HIGH Cisco IOS XE Software Security Hardening Release
CVE-2026-20269 8.6 HIGH Cisco IOS XE Software Security Hardening Release
CVE-2026-20270 8.6 HIGH Cisco IOS XE Software Security Hardening Release
CVE-2026-20273 8.6 HIGH Cisco IOS XE Software Security Hardening Release
CVE-2026-20301 8.6 HIGH Cisco IOS Software and IOS XE Software Extensible Messaging Client Protocol Denial of Serv
CVE-2026-20313 7.7 HIGH Cisco Catalyst SD-WAN Security Hardening Release - Memory Corruption Vulnerabilities
CVE-2026-20124 7.7 HIGH Cisco IOS XE Software SNMP Denial of Service Vulnerability
CVE-2026-20288 6.5 MEDIUM Cisco IMC Remote Code Execution Vulnerability Remote Code Execution Vulnerability
CVE-2026-20294 6.5 MEDIUM Cisco Catalyst SD-WAN Manager Information Disclosure Vulnerability
CVE-2026-20311 6.3 MEDIUM Cisco IOS XE Software Web UI Denial of Service Vulnerability
CVE-2026-20289 5.7 MEDIUM Cisco RoomOS Logging Subsystem Information Disclosure Vulnerability
CVE-2026-20028 5.0 MEDIUM Cisco Terminal Services Agent Firewall Rules Bypass Vulnerability

Showing top 20 of 23 CVEs. View all on vendor page → →

IV. Related Vulnerabilities

Same product: Cisco IOS XE Software
Same vendor: Cisco
Same weakness: CWE-691

V. Comments for CVE-2026-20271

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