Bug Bounty is a super competitive field and if you want to stay ahead of other hunters, you need to seriously know what to look for, instead of blindly shooting in all directions.

Bug classes might become more or less prevalent depending on factors such as: “Are Bug Hunters looking for it?”, “Are developers making this mistake?”, “Does an LLM produce code with that vulnerability?”, etc…

Web LLM Attacks

A couple of years ago, companies rushed to integrate AI models into their services. At the time, a lot of hunters scored some generous bounties looking for flaws in these systems.

Fast forwarding to 2026, a lot of these AI Models have been coupled with RAGs (a RAG is what allows an LLM to read the documents and files you provide it) and Internal APIs to increase their capabilities and usefulness.

This is all lovely, however, it opens a big attack surface which Bug Hunters can exploit.

What I have been noticing from reading other Hunters’ writeups and in general keeping up with Hackerone’s Hacktivity, is that a lot of hunters seemingly forgot about hunting for bugs in LLMs altogether.

Take a look at all the different AI-related vulnerabilities mentioned in Bugcrowd’s VRT:

As you can see, there are endless bugs related to LLMs you can exploit!

The main bugs you can probably find on most targets who implement these AI features are Prompt Injection, System Prompt Leakage, and Leakage of Training Data (or Company data embedded via RAG).

Insufficient Rate Limiting and HTML injection should also be pretty easy to find in this kind of infrastructure.

I will write an article soon where I dive deeper into these bugs and on how to find them in real targets.

Credential Stuffing

Credential Stuffing has been on the rise recently, and so has been companies’ awareness of it.

More and more companies are realising how dangerous Leaked Credentials can be, because of all the different implications they can have.

For instance, depending on the credentials that attackers find, they might be able to have access to Admin Panels, have access to content that should only be available behind a paywall, have access to internal data, etc…

If you want to find Leaked Credentials for your Bug Bounty targets, you are going to need a Data Breach search engine. You have several good options (like the ones I present in this article), but I am currently using BreachCollection because I find it to have the best interface and value.

In order to gather Leaked Credentials, you first need to determine whether you are looking for Internal Credentials or User Credentials.

If you are looking for internal credentials, you will mostly need to perform “Email-Domain Queries”. In this type of query, BreachCollection retrieves all the credentials whose email domain corresponds to your target (“[email protected]“).

If you are looking for user credentials, you need to perform “Domain Queries”. In this type of query, BreachCollection will retrieve all the credentials that log you in to your target domain.

Sometimes, you might find also employee/internal credentials via Domain Queries, like I did in this write-up.

Finding Leaked Credentials became such an important step in my Bug Bounty Recon that I created a tool which integrates the BreachCollection API to automatically gather the Leaked Credentials from my target at the same time it grabs all the URLs in the Wayback Machine. You can check it out here.

I also set email alerts in the BreachCollection Dashboard so I get a notification every time new credentials come up for one of my favorite Bug Bounty targets, so I can check them out quickly and report them.

Race Conditions

These are some of the coolest bugs you can find in a Web Application.

It occurs when the time of checking a constraint and the time of executing an action form a window large enough for an attacker to exploit.

There are actually several reasons why Race Conditions will become easier to find this year. A couple of years ago, most big companies started moving from a Monolithic Design (all of the components of their services ran on a single server), to a Microservices design (different servers run different services).

The Microservices architecture is far more susceptible to Race Conditions than the Monolithic Architecture, because Database Locking (the process of not allowing the database to be modified while it is already being modified by another process, thus, solving race conditions) is a lot harder to do in a Microservices architecture.

Moreover, with the growing popularity of AI amongst developers, there is less and less awareness to this sort of issue, and a bigger focus on simply shipping products faster.

Solving Race Conditions, as a developer, is something that actually takes some careful reasoning about. This makes Race Conditions a perfect opportunity for you to get more successful at Bug Bounties.

In case you want to learn with more detail how this Bug works, you can check out my article where I go over what you need to become a Pro in Race Conditions.

Conclusion

As the trends in Web Development change, our methodologies as Bug Hunters must evolve too.

Whether it is the bigger attack surface of AI integrations, the threat of Leaked Credentials, or the challenges introduced by the Microservices architecture leading to Race Conditions, the opportunities are abundant for those willing to look where others aren’t.

Make sure to write any questions in the comments!

Happy Hunting, and a prosperous 2026!