The Best Free Threat Intelligence Feeds

You don't need an enterprise budget to stay informed about cyber threats. There's a wealth of free threat intelligence feeds — from government agencies, vendor research teams, community projects and news aggregators — that together cover most of the threat landscape. This guide rounds up the best free sources, what each is good for, and how to combine them into a workable program.

First, a quick distinction. "Feed" can mean two things: a stream of machine-readable indicators you pipe into security tools, and a stream of human-readable reporting you monitor for situational awareness. The best programs use both.

Government and CERT feeds

Government sources are authoritative, free, and especially strong on actively exploited threats:

• CISA (US) — alerts, advisories, and the invaluable Known Exploited Vulnerabilities (KEV) catalog, which lists vulnerabilities with confirmed in-the-wild exploitation. If you patch by anything, patch by this.
• NCSC (UK) — advisories and threat reports.
• JPCERT/CC (Japan) and other national CERTs — regional and global threat reporting.
• The NVD — the National Vulnerability Database, the canonical source for CVE details and CVSS scores.

Community and indicator feeds

Community-driven projects provide high-quality, free indicators:

• abuse.ch — a suite of excellent free feeds: URLhaus (malicious URLs), ThreatFox (IOCs), MalwareBazaar (malware samples) and Feodo Tracker (botnet C2).
• AlienVault OTX — a large community exchange of "pulses" with indicators and context, accessible via a free API.
• Spamhaus and emerging-threats rules — reputation data and detection signatures.
• MISP communities — many sharing groups distribute curated indicators via the open-source MISP platform.

Vendor research feeds

Leading security vendors publish detailed, free threat research — often the first place new campaigns, malware families and APT activity are documented. Teams from across the industry (incident responders, malware analysts and threat-intelligence units) regularly release write-ups that include indicators and TTPs. The catch is volume: there are dozens of high-quality vendor blogs, and monitoring them all by hand is impractical.

News and aggregated feeds

For situational awareness — knowing what's breaking right now — security news outlets and aggregators are essential. The challenge is that the same major story gets reported by many outlets simultaneously, creating duplication and noise.

This is exactly the problem TI News Feed solves. It aggregates dozens of authoritative public sources — government advisories, vendor research and top security newsrooms — then deduplicates near-identical stories and ranks everything by priority, so you get one clean, real-time stream instead of a flood. It's free, updates every five minutes, and links each item back to its original source. For most teams, it's the single most efficient way to consume the human-readable side of threat intelligence.

How to combine free feeds effectively

More feeds is not automatically better — unmanaged, they create duplication and alert fatigue. A practical approach:

1. Situational awareness: monitor one good aggregated news feed plus government advisories for what's happening now.
2. Indicators: ingest a few high-quality community feeds (abuse.ch, OTX) into your tools — and expire them aggressively, since indicators perish quickly.
3. Deep research: follow vendor reports for the campaigns most relevant to your sector, and extract their TTPs.
4. Prioritization: use CISA KEV and exploitation data to decide what to patch first.
5. Deduplicate and curate: favor signal over volume; a few trusted, deduplicated sources beat a dozen noisy ones.

Store and correlate it all in a free platform like MISP or OpenCTI if you want to operationalize indicators — see our guide to open-source threat intelligence tools.

When to consider paid feeds

Free feeds cover an enormous amount, but paid intelligence adds value in specific areas: finished, analyst-written reporting tailored to your industry; dark-web and underground monitoring; faster, curated indicators with confidence scoring; and dedicated analyst support. Many organizations start entirely on free sources and add paid intelligence only once they've matured their program and identified concrete gaps.

How to evaluate a threat feed's quality

Not all feeds are created equal, and the number of indicators a feed contains tells you almost nothing about its value. A feed of a million stale, context-free indicators is worse than useless — it floods your tools and buries the few entries that matter. When assessing any feed, free or paid, weigh it against these quality dimensions:

• Relevance. Does it cover the threats, sectors and technologies that actually matter to you? A feed packed with indicators irrelevant to your environment just adds noise.
• Timeliness. How quickly does it surface new threats? In a landscape where indicators perish in days, a feed that's hours fresh is far more valuable than one updated weekly.
• Accuracy and false positives. A feed that flags legitimate infrastructure as malicious will erode trust and waste analyst time. Low false-positive rates are essential.
• Context. Does each entry come with the campaign, confidence level, source and date — or is it a bare indicator? Context is what lets you act with confidence.
• Confidence scoring. The best feeds indicate how sure they are about each item, letting you tune how aggressively you act.
• Uniqueness. Does it add anything you don't already get elsewhere, or just duplicate other feeds?
• Format and integration. Standards support (like STIX/TAXII) and clean formatting determine how easily you can ingest it.

A practical approach is to start with a small number of feeds that score well on relevance and timeliness, measure how many of their alerts turn out to be genuinely useful, and prune anything that consistently adds noise. The goal is a curated, high-signal set — not the longest possible list of subscriptions. This is also why deduplication and prioritization matter so much when consuming the human-readable side: a feed that collapses the same story reported by twenty outlets into one ranked item respects your attention far more than twenty raw headlines. Quality, relevance and signal density beat raw volume every time.

The bottom line

A capable threat-intelligence program can run almost entirely on free feeds: CISA KEV and government advisories for actively exploited threats, abuse.ch and OTX for indicators, vendor blogs for deep research, and an aggregated, deduplicated news feed for real-time awareness. The smartest place to start is the one that saves the most time — watching the whole landscape in one clean stream. That's what our live threat intelligence feed delivers, free, updated every five minutes and ranked by priority.