EUVD-2026-70207
GHSA-h893-gcq5-j4cv
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessObtain low-privilege IOS XR credentials
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DeliveryReach management-plane interface over network
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ExploitSend crafted input triggering exceptional-condition flaw
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ExecutionTrigger CWE-703 memory/logic error
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ImpactAchieve full C:H/I:H/A:H router compromise
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A10:2025 - Mishandling of Exceptional Conditions
ASVS 5.0
V16 - Security Logging and Error Handling Exception handling framework
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| Exploitation Conditions | Exploitation requires an authenticated session with at least low-privilege credentials on a reachable Cisco IOS XR management interface (SSH, NETCONF, gRPC, or similar). The CVSS PR:L metric confirms some level of authentication is prerequisite - unauthenticated exploitation is not indicated. No specific feature toggle or non-default configuration is identified in the advisory description, suggesting the vulnerable code path may be present in default IOS XR deployments. Limiting factors include: (1) the attacker must possess valid IOS XR credentials, (2) management-plane access must be network-reachable, and (3) the exact trigger condition and vulnerable subsystem are not publicly disclosed, which currently limits opportunistic exploitation. |
| Impact | The CVSS 8.8 vector (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) signals a high-severity, network-exploitable vulnerability requiring only low-privilege authentication - a realistic threat in environments where device credentials may be broadly distributed across NOC staff or where SSH access is available to multiple users. Even a mid-sized network operations team should treat this as urgent patching given the full C:H/I:H/A:H triad and no scope constraint. However, the description is deliberate boilerplate from a batch internal-review advisory, and the precise exploitation mechanism for CWE-703 is not disclosed; the 8.8 score cannot be independently verified from the available text. No EPSS data was provided, KEV status is negative (no confirmed active exploitation), and no public proof-of-concept is available. The risk profile is moderately elevated by the authenticated-but-low-privilege requirement - IOS XR management-plane credentials, while not trivially obtained, are accessible to a wider pool of insiders and supply-chain actors than full admin credentials. Priority should reflect network-criticality: IOS XR core routers represent high-value targets where integrity or availability loss has outsized business impact. |
| Exploit ScenarioDerived | An attacker who has obtained low-privilege IOS XR credentials - for example, through credential stuffing, an insider threat, or supply-chain compromise of a NOC tool - sends crafted protocol messages or API requests that trigger an improper exceptional-condition handling path. The failure to correctly handle the condition leads to memory corruption or logic error that escalates to full confidentiality, integrity, and availability compromise of the router. No public proof-of-concept exists, but the low complexity score means exploitation is not considered technically demanding once the trigger condition is identified. |
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Alert meAnalysisAIv1 – Sep 02, 2026
Improper handling of exceptional conditions (CWE-703) in Cisco IOS XR Software allows an authenticated, remote attacker with low-privilege credentials to achieve high-impact compromise of confidentiality, integrity, and availability. The vulnerabilities were discovered internally by Cisco's security engineering team during a proactive review and are addressed in a software hardening release. No public exploit or active exploitation has been identified at time of analysis, but the CVSS 8.8 score and full C:H/I:H/A:H impact profile make this a significant risk for service-provider and enterprise core-network operators running affected IOS XR releases.
RemediationAI
Apply the Cisco-provided hardening release as detailed in the advisory at https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-iosxr-qg64NcM. No specific fixed version number is disclosed in the available data - consult the advisory's Software Fixed Releases table to identify the correct target train for your hardware platform. As a compensating control while patching is scheduled, restrict IOS XR management-plane access (SSH, NETCONF, gRPC) to trusted administrative IP ranges using control-plane policing (CoPP) or management-plane protection (MPP), and enforce least-privilege RBAC so only required accounts hold management credentials. Note that MPP and CoPP reduce attack surface but do not eliminate risk for authenticated users who already have low-privilege access.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in euvd
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Technical ContextAI · show details
Cisco IOS XR is Cisco's carrier-grade network operating system deployed on ASR 9000, NCS, CRS, and related platforms used in service-provider backbones and large enterprise core networks. CWE-703 (Improper Check or Handling of Exceptional Conditions) describes a class of flaws where software fails to correctly anticipate or respond to error states, boundary conditions, or unexpected inputs - which in network OS contexts can manifest as memory corruption, resource exhaustion, or logic bypasses with downstream privilege or code-execution implications. The affected CPE cpe:2.3:a:cisco:cisco_ios_xr_software:*:*:*:*:*:*:*:* covers all IOS XR software versions without a specified upper bound, suggesting the vulnerability is widespread across the product line. This CVE is part of a batch hardening advisory (cisco-sa-hardening-iosxr-qg64NcM) that groups multiple internally discovered issues, which limits per-vulnerability technical specificity.
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Severity by source
AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Vendor-supplied vector adopted; PR:L confirmed by authentication requirement, full triad impact plausible for network-OS exceptional-condition flaw.
Primary rating from Vendor (cisco).
CVSS VectorVendor: cisco
DescriptionCVE.org
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-2026-20280 are related to improper checking or handling of exceptional condition issues that are grouped under the Common Weakness Enumeration (CWE) CWE-703.
Executive ViewAI
Cisco IOS XR Software vulnerability (CWE-703) allows low-privilege authenticated users to fully compromise confidentiality, integrity, and availability on mission-critical routing and switching infrastructure. This risk is particularly acute for service providers and enterprises with customer-facing network equipment, as no vendor patch currently exists and the flaw is exploitable through routine user accounts.
No vendor-released patch identified at time of analysis. Interim mitigations: enforce multi-factor authentication for all IOS XR administrative access, implement role-based command restrictions to prevent privilege-escalation operations by low-privilege accounts, enable comprehensive audit logging of configuration and permission changes, isolate management network segments to limit lateral movement, and conduct weekly reviews of user activity logs to detect exploitation attempts.
Threat Intelligence Overview
NVD
CVE.org
EPSS
Vulnrichment
VulDB
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
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