The most useful threat intelligence resources available to a small security team in 2026 aren’t hidden behind a sales call — they’re published by the U.S. government and by MITRE, free, and already the foundation most commercial platforms are built on. This roundup skips the vendor landscape entirely and focuses on the authoritative sources and the analyst tooling built directly on top of them, sized for a team without a dedicated CTI analyst.
NIST’s National Vulnerability Database (NVD)
NVD is the authoritative public record for CVEs — CVSS scoring, CWE classification, affected products, and reference links — maintained by the National Institute of Standards and Technology and published through a free API. For a small team, NVD is the ground truth every vulnerability decision should trace back to: not a vendor’s restatement of a CVE, but the record itself.
CISA’s Known Exploited Vulnerabilities (KEV) Catalog
Where NVD tells you how severe a vulnerability is in theory, CISA’s KEV catalog tells you which vulnerabilities are being exploited right now. Entries are added on a rolling basis as CISA confirms active exploitation, and Binding Operational Directive 22-01 requires federal civilian agencies to remediate them on a set timeline — a cadence that’s become the de facto patch-priority signal well beyond the federal government. For a small team deciding what to patch first, a CVE’s presence on KEV is one of the highest-value single facts available, and it’s free.
MITRE ATT&CK
MITRE ATT&CK is the authoritative, publicly maintained taxonomy of adversary tactics and techniques, developed with DHS/CISA sponsorship and used across the industry as a common reference for describing how an attack actually unfolds. For a small team, ATT&CK turns a vague incident narrative into a structured, comparable technique ID — useful for briefing leadership, mapping detection coverage, and understanding how a specific threat actor or malware family operates without inventing your own taxonomy.
Quietlytic’s vulnerability, threat-actor, and campaign research
Quietlytic turns the three sources above into daily, readable analysis: vulnerability advisories that trace severity and exploitation status back to NVD and CISA KEV, threat-actor and malware profiles built on MITRE ATT&CK’s own relationship data, and active campaign tracking that connects the two. It’s the synthesis layer a small team without a dedicated analyst needs — built specifically on authoritative sourcing rather than a proprietary black-box score — and it continues to grow toward a fuller intelligence product purpose-built for teams operating at exactly this scale.
Quietlytic’s browser-local analyst tools
Alongside the research, a growing set of tools lets an analyst verify a claim or work a piece of evidence without standing up any infrastructure:
- The CVSS calculator decodes or builds a CVSS v3.1 vector, so a reported severity score can be checked rather than trusted blindly.
- The ATT&CK technique lookup resolves a technique ID or name against MITRE’s own dataset, with tactics and sub-technique parents shown.
- IOC extraction, defanging, and normalization tools pull indicators out of raw text or logs and get them into a consistent, usable format.
- The STIX bundle viewer reads a STIX 2.1 bundle — the standard structured-intelligence format — as browsable objects instead of raw JSON.
- The hash identifier narrows an unlabeled hash down to the algorithms that could have produced it during triage.
Every one of these runs locally in the browser — nothing typed in is sent to a server — which matters for a small team handling sensitive indicators without a dedicated data-handling policy in place yet.
How to build a workflow from this list
Start from CISA KEV for what’s urgent, cross-reference against NVD for the full technical picture, and use MITRE ATT&CK to describe how the attack actually works once you’re past the “is this exploited” question. Layer Quietlytic’s research on top for the daily synthesis a small team doesn’t have time to produce alone, and use the analyst tools to verify any claim — your own or anyone else’s — before it drives a decision. For the reasoning behind grounding a small team’s workflow in these sources specifically, see our buyer’s guide to threat intelligence platforms for small teams, and for the step-by-step evaluation process, see how to choose a threat intel platform when your SOC team is small.
Frequently Asked Questions
What’s the most important free CTI resource for a small security team? CISA’s KEV catalog, because it answers the single highest-leverage question in vulnerability management — is this actually being exploited right now — as a confirmed fact rather than a theoretical severity score.
Is MITRE ATT&CK difficult for a small team to start using? Not for the core use case of describing and comparing techniques. The full framework is large, but a small team typically only needs to look up and reference specific technique IDs as they come up in an incident or advisory, which the ATT&CK technique lookup tool is built for.
Why do Quietlytic’s tools run locally instead of through a server? Indicators, hashes, and STIX bundles handled during an investigation are often sensitive. Running extraction, decoding, and lookup tools entirely in the browser means nothing pasted into them is transmitted anywhere, which matters for a small team without a formal data-handling policy yet in place.
Do I still need NVD and CISA KEV directly if I’m using Quietlytic’s research? Quietlytic’s research traces every claim back to those sources specifically so you can verify it yourself — the goal is transparency, not replacing the primary source. Checking the underlying NVD or KEV record is always available and worth doing for anything driving a high-stakes decision.
Grounded in the National Vulnerability Database (NVD), CISA’s Known Exploited Vulnerabilities (KEV) catalog, and MITRE ATT&CK. See more vulnerability research.