Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HSummary
CVE-2026-26171 is a high-severity Uncontrolled Resource Consumption (CWE-400) vulnerability in Microsoft .Net. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked in the top 24% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to CM-6 (Configuration Settings) and SA-11 (Developer Testing and Evaluation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
Uncontrolled resource consumption affects the .NET platform and is tracked as CVE-2026-26171. The flaw, assigned CWE-400 and CWE-611, permits remote attackers to trigger excessive resource use that leads to denial of service. It carries a CVSS 3.1 base score of 7.5 reflecting network attack vector, low complexity, and no required privileges or user interaction.
An unauthenticated attacker with network access can send crafted input that exhausts resources on affected .NET systems, resulting in service disruption without any impact on confidentiality or integrity. The current and peak EPSS scores both stand at 0.0308, indicating no material increase in exploitation probability since disclosure.
Microsoft publishes guidance for the issue at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26171.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-22404
Vulnerability Data
Uncontrolled resource consumption in .NET allows an unauthorized attacker to deny service over a network.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.5.1V15.3.2
Mitigating Controls (NIST 800-53 r5) AI
Secure configuration settings can disable external entity processing in XML parsers.
Developer testing can discover XXE flaws through targeted XML parsing tests.
SC-5 directly limits the effects of resource-exhaustion events that constitute uncontrolled consumption.
SC-6 enforces explicit allocation limits on resources, structurally preventing the weakness from occurring.
Input validation can reject or sanitize XML containing external entity references.
Least-functionality configuration can prohibit unsafe DTD features or external entity resolution.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly prevent introduction of improper recursive entity handling in XML code.
Explicitly requires monitoring and maintaining resource capacity, directly addressing uncontrolled consumption to preserve availability.
Hardened XML parser configurations directly disable external entity resolution.
Continuous monitoring of computing resources can detect resource exhaustion but does not itself enforce allocation limits.
Vulnerability scanning can discover XXE flaws but does not prevent their introduction in code.
Resilience mechanisms such as avoiding single points of failure indirectly reduce impact of resource exhaustion.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Resource-utilization monitoring and alerting on bottlenecks or overloads limits the impact of denial-of-service or resource-exhaustion attacks.
Security testing in development catches XXE via static analysis and dynamic XML fuzzing.
By continuously monitoring utilization, stress-testing peak loads, and maintaining documented plans to scale or throttle resources, the control directly limits an attacker’s ability to drive a system into uncontrolled resource exhaustion.
Vulnerability management identifies and patches XML libraries with unsafe default entity settings.
Pre-agreed severity-based prioritization and resource allocation during incident triage reduce the likelihood that an attacker-induced resource exhaustion will overwhelm the organization before corrective action is taken.
Business-continuity plans that include resource-management controls reduce the likelihood that an attacker can trigger uncontrolled resource consumption by forcing the system into a degraded or fallback state.