# Microsoft Defender Vulnerability Management vs Tenable Nessus: which do AI models recommend for vuln management, October 2026

IT AI Recommendation Index, October 2026 Edition, Vulnerability management platforms. Zero of fourteen models named Microsoft Defender Vulnerability Management first on the direct prompt; zero named Tenable Nessus. Page: https://it-ai-index.com/security/vulnerability-management-platforms/microsoft-defender-vulnerability-management-vs-tenable-nessus/

| | First-choice share | Rank | Negative rate | Labels | Models naming it |
|---|---|---|---|---|---|
| Microsoft Defender Vulnerability Management | 4% | #6 of 10 | 13% | 23 | 10 of 14 |
| Tenable Nessus | 4% | #8 of 10 | 30% | 23 | 11 of 14 |

## The direct prompt, model by model

- Gemini 3.5 Flash: neither first, one named (first choices: SecPod SanerNow, Vicarius vRx) (alternatives: CrowdStrike Falcon Spotlight, Microsoft Defender Vulnerability Management, Nucleus Security, Rapid7 InsightVM)
- Perplexity Sonar: neither first, one named (first choices: Rapid7 InsightVM) (alternatives: ManageEngine Vulnerability Manager Plus, Microsoft Defender Vulnerability Management, Microsoft Defender for Cloud, Qualys VMDR, Vicarius vRx)
- GLM 4.7 FlashX: neither first, one named (first choices: Qualys VMDR) (alternatives: ManageEngine Vulnerability Manager Plus, Microsoft Defender Vulnerability Management, Tenable Vulnerability Management)
- Claude Haiku 4.5: neither named (first choices: Rapid7 InsightVM) (alternatives: ManageEngine Vulnerability Manager Plus, Microsoft Defender for Cloud, Tenable Vulnerability Management, Vicarius vRx)
- GPT-5.4 mini: neither named (first choices: Rapid7 InsightVM) (alternatives: Qualys VMDR, Tenable Vulnerability Management)
- Grok 4.1 Fast: neither named (first choices: Rapid7 InsightVM) (alternatives: Intruder, ManageEngine Vulnerability Manager Plus, Qualys VMDR, Tenable Vulnerability Management)
- Mistral Small: neither named (first choices: Rapid7 InsightVM) (alternatives: Intruder, ManageEngine Vulnerability Manager Plus, SureCloud)
- DeepSeek V4 Flash: neither named (first choices: Rapid7 InsightVM, Vicarius vRx) (alternatives: Intruder, Tenable Vulnerability Management)
- Llama 4 Maverick: neither named (first choices: Intruder) (alternatives: ManageEngine Vulnerability Manager Plus, Rapid7's Insight platform)
- Qwen 3.7 Flash: neither named (first choices: Rapid7 InsightVM) (alternatives: Qualys VMDR, Tenable Vulnerability Management)
- Kimi K2: neither named (first choices: Intruder, Rapid7 InsightVM) (alternatives: Qualys VMDR)
- MiniMax M2.5: neither named (first choices: Rapid7 InsightVM) (alternatives: Intruder, Tenable One)
- GPT-6 Luna: neither named (first choices: Tenable Vulnerability Management) (alternatives: Qualys VMDR, Rapid7 InsightVM)
- Muse Glimmer 30B: neither named (first choices: Rapid7 InsightVM) (alternatives: Intruder, ManageEngine Vulnerability Manager Plus)

## What the models said about Microsoft Defender Vulnerability Management

- "Limitations: Feature depth drops outside Windows ecosystem; limited Linux/macOS capabilities" (Kimi K2, comparative prompt, soft negative)
- "they should not be your *only* vulnerability management platform" (Gemini 3.5 Flash, negative prompt, soft negative)
- "Multi-tenant features are disappointing" (DeepSeek V4 Flash, negative prompt, soft negative)
- "for a tight budget, I'd start with Microsoft Defender Vulnerability Management if you already use Microsoft 365 or Defender" (GPT-6 Luna, budget prompt, first choice)
- "Microsoft Defender Vulnerability Management (free trial / included...) for risk‑based prioritization and remediation" (GLM 4.7 FlashX, budget prompt, first choice)
- "Microsoft-heavy environment: Evaluate Microsoft Defender Vulnerability Management first if you already use Microsoft Defender for Endpoint P2" (GPT-6 Luna, paraphrase prompt, alternative)

## What the models said about Tenable Nessus

- "Avoid trying to scrape out a "Free" version of Nessus; Tenable discontinued its unlimited community scanner" (Qwen 3.7 Flash, budget prompt, hard negative)
- "Avoid Standalone "Point-in-Time" Scanners for Enterprise VM ... Why to avoid them for enterprise VM" (Gemini 3.5 Flash, negative prompt, hard negative)
- "scanners like older Nessus/OpenVAS versions criticized for inaccurate Windows scans or signature mismatches" (Grok 4.1 Fast, negative prompt, soft negative)
- "the best starting point is Nessus Essentials (free) + a free vulnerability feed for on‑prem scanning" (GLM 4.7 FlashX, budget prompt, first choice)
- "I'd recommend Tenable Nessus Professional as the starting point" (Grok 4.1 Fast, paraphrase prompt, first choice)
- "useful for getting started with proven scanning technology, with the limitation of scan limits and lack of centralized reporting" (Muse Glimmer 30B, budget prompt, alternative)

Share is the count of first choices across the direct, paraphrase, budget and scale prompts over all fourteen models, for a mid-market B2B company; rank is within the category. Comparisons are drawn for the top eight products in each category. Published under CC BY 4.0; the output is the models' output, and nothing here is a recommendation by the index.