Introducing context-aware vulnerability discovery and remediation with Cloudflare Managed Defense and OpenAI Daybreak models

Your scanner just flagged 4,000 new vulnerabilities, 78 of them critical. Which one do you fix first?

To answer that question, Cloudflare is announcing early access to Vulnerability Discovery and Remediation, now part of Cloudflare Managed Defense. Vulnerability Discovery and Remediation is a new, invitation-only Cloudflare service that helps customers detect and mitigate vulnerabilities in their codebases.

Through the OpenAI Daybreak Defense Network, we use OpenAI Daybreak models, including GPT-5.6 Cyber, for reconnaissance, hunting, and validation against codebases that you authorize us to access. If we detect a vulnerability, we will then propose solutions to you, automatically checking each proposed patch and any accompanying proposed mitigation before presenting them for review. Importantly, you are in the driver’s seat: while we may propose code patches and other mitigations, you decide whether they are implemented.

Choosing what to fix first has always been hard. It's getting harder. Large language models can now surface weaknesses across a codebase in minutes, which means the number of findings keeps climbing. But the real problem is speed. Attackers can use AI to accelerate parts of vulnerability discovery and exploitation, giving security teams and developers less time to decide what matters and act on it.

Imagine that your scanner tells you there's a vulnerability in a handler. It doesn't tell you whether that code is deployed. It doesn't tell you whether anyone is actually hitting that route, what security activity surrounds it, or what controls you already have in place. You have to prioritize the finding without evidence of its production exposure or the protections already in place.

This is where we can help. With our global network, we can see which routes are active, how much traffic they carry, and what security events surround them. When customers enable Vulnerability Discovery and Remediation with Web Application Firewall (WAF), we can also see what rules are already applied and are actively blocking attacks. That context turns a generic finding into a specific priority: this vulnerability is in code that's live, on a route that's heavily used, with recent attack activity and no existing protection. And we can help you mitigate that vulnerability by proposing custom WAF mitigations and code patches tailored to your systems.

If this sounds familiar, it should. In “Build your own vulnerability harness”, we described the model-agnostic pipeline we use to scan Cloudflare's fleet, adversarially validate every finding, and turn raw model output into fixes engineers can trust. That internal system is one pillar of Vulnerability Discovery and Remediation. The harness gave us a way to find bugs at fleet scale. Vulnerability Discovery and Remediation brings that discovery process to the code the customer authorizes us to inspect, then connects the findings to production traffic, security events, and the edge controls that can act on them.

This diagram provides an overview of our process, which we explain in more detail below.

Adding context to a vulnerability harness

Our solution works across Cloudflare Workers and proxied applications. The process of detecting vulnerabilities begins with the collection of a traffic and security data snapshot from Web Assets and WAF. The snapshot shows which routes are active, how much traffic they receive, and whether recent security events are associated with them. For instance, a path exhibiting a high volume of detection triggers may also be considered critical for security context purposes. Web Assets and WAF itself serve as the first and second pillar of Vulnerability Discovery and Remediation respectively.

Next, we use source code vulnerability analysis to identify potential weaknesses in code. But that analysis does not show which routes reach it, how much traffic those routes receive, whether they receive suspicious requests, or which protections already apply. We treat routes carrying a high volume of requests as hot paths. Source code deployed to these routes undergoes stricter security profiling. Together, these signals provide evidence about how the API is used and where a vulnerability may be exposed.

For Workers, we retrieve the most recent source version of the Worker and its configured routes to identify the endpoints the Worker serves. Next, we match the Worker's routes to Web Assets and request metadata from Workers Observability, tying the exact source under review to the endpoints it handles in production. This collected network context stays available throughout the investigation, allowing agents to pull it when they need it. 

Our vulnerability harness then starts up. It begins by using the Reconnaissance agent to map request paths to the parts of the codebase that handle them. Reconnaissance uses that map to send hunter agents into specific sections of the customer-authorized code, where they look for vulnerabilities and pull in relevant network context as needed. That context can help the hunter agents pay more attention to code behind an active or recently targeted route, but it does not establish that a vulnerability exists. Every vulnerability finding has to be corroborated by evidence in the source code.

Once the hunters return their findings, the validation stage checks the proposed mitigations before assigning each vulnerability an initial risk rating based on source code. The network evidence we collect can raise that rating further when, for example, the affected endpoint carries significant traffic or shows signs of active probing.

The result is a prioritized list of findings, each with a recommended code patch and, when the evidence supports it, a Cloudflare WAF Custom rule that can reduce exposure while the code fix is reviewed. If you have authorized our VDR to defend your zone, we will deploy the rules, scoped conservatively around the method, path, and other request details needed to reach the vulnerable code. If a route pattern contains only variables and wildcards, we do not suggest a rule. We would rather miss a possible connection than claim one the evidence cannot support.

The HTTP method override bypass example above shows how these signals work together. The harness maps the source finding to the production route, uses traffic and security activity to prioritize it, and scopes a proposed WAF rule around the requests that can reach the vulnerable code. That rule can reduce exposure while engineering reviews and ships the code patch.

Where the model runs

When you authorize an investigation, Vulnerability Discovery and Remediation runs the harness on Cloudflare and sends model prompts from Workers through Cloudflare AI Gateway to OpenAI Daybreak models on OpenAI's servers. GPT-5.6 Cyber is used during reconnaissance, hunting, and validation, and its responses return to the harness so the workflow can continue on Cloudflare. No model inference runs at Cloudflare's edge, and the model cannot apply any patch or rule it proposes.

We keep each investigation narrow by limiting it to the source code and evidence the customer authorizes. Before that context reaches the model, Vulnerability Discovery and Remediation removes what the investigation does not need and applies the redaction controls configured for the engagement. The harness treats source code, logs, and request metadata as evidence to inspect, rather than instructions to follow.

Tool access follows the same boundary: each call is logged and checked against the investigation's access policy before it runs, and every patch or rule proposal must pass checks implemented outside the model. If one of those checks fails, the workflow stops before the proposal reaches customer review.

Nothing is presented for review until it has cleared the checks and our team validates the output. For an edge-defense suggestion, that means validating the rule syntax and running it against synthetic fixtures that represent expected requests, rather than against customer traffic. If a check fails or the result remains ambiguous, we hold the output back and route it for diagnosis.

Passing those checks still does not change your environment. After validation by our team, Vulnerability Discovery and Remediation prepares the source code patch and WAF rule.

Join early access

Vulnerability Discovery and Remediation is available to selected customers by invitation during early access through our Managed Defense team. Each engagement starts with one application whose codebase the customer authorizes us to investigate. To connect the findings to production, Vulnerability Discovery and Remediation uses authorized read access to the Web Assets operation inventory, the relevant WAF controls, and Workers Trace Events Logpush where available. The investigation is semi-automated, but you review every result before deciding whether to test or deploy a change.

If you're interested in learning more, talk to your Cloudflare account team.