Guides

Business logic vulnerabilities are the ones that slip through scanners completely. No CVE, no exploit-db entry, no Nuclei template. Just a gap between what the application intends to do and what it actually does when you push it sideways. They’re also some of the most valuable findings you can report. High business impact, hard to auto-detect, and often sitting in production for years because nobody thought to test them. This guide covers how to find them, how to exploit them, and what real business logic attacks look like in practice. ...

Insecure deserialization has handed attackers RCE in some of the most hardened enterprise environments on the planet — Apache, Jenkins, JBoss, WebLogic, Oracle, and more. A single malformed object can bypass authentication, execute arbitrary code, or delete your entire database. This guide covers detection, exploitation, gadget chains, and WAF bypass for Java, PHP, Python, and .NET in 2026. What Is Deserialization? Serialization converts an object in memory into a format that can be stored or transmitted — bytes, JSON, XML, binary. Deserialization reverses it: takes the stored format and reconstructs the object. ...

Server-Side Template Injection (SSTI) is one of the most dangerous web vulnerabilities you’ll encounter. A simple {{7*7}} in the right field can hand you full remote code execution on a production server. This guide covers everything — detection, fingerprinting, exploitation, WAF bypass, and defense — for every major template engine in 2026. What Is SSTI? Web frameworks use template engines to render dynamic content — think Flask with Jinja2, PHP apps with Twig, Java apps with FreeMarker. When user input is concatenated directly into a template string rather than passed as a variable, the template engine evaluates it. That’s SSTI. ...

File inclusion vulnerabilities are deceptively simple on the surface — you trick an application into loading a file it shouldn’t. But the exploitation paths they open up range from sensitive data disclosure all the way to full remote code execution. Log poisoning, PHP filter chains, session file injection, null byte tricks — this vulnerability class has more depth than most. If you’re doing web app pentesting or bug bounty hunting in 2026, you’ll encounter file inclusion regularly. PHP applications are the most common target, but the patterns appear in other languages too. This guide covers LFI and RFI from first principles through advanced exploitation. ...

Command injection is one of the most dangerous vulnerability classes in web security. Not because it’s subtle — it’s actually one of the most direct paths to full system compromise. You inject a shell command through a web input, the server executes it, and suddenly you’re running arbitrary code on someone’s infrastructure. OWASP has kept injection in its Top 10 for over a decade for good reason. When you find command injection, the game changes. It’s not “I can read a record I shouldn’t.” It’s “I own this server.” ...

Insecure Direct Object Reference (IDOR) is consistently one of the highest-impact vulnerabilities in web applications and APIs — and it’s one of the easiest to miss during a standard pentest if you don’t know where to look. It doesn’t require complex payloads. No memory corruption. No custom shellcode. You find an ID, swap it for another ID, and suddenly you’re reading someone else’s data. Or deleting it. Or taking over their account. ...

XML External Entity (XXE) injection is one of the most dangerous web application vulnerabilities — capable of reading server files, triggering SSRF, and achieving remote code execution in the right conditions. It’s been in the OWASP Top 10 for years, and it’s still alive in production systems everywhere. The reason: developers enable XML parsers with external entity processing on by default and never turn it off. This guide covers detection, exploitation, out-of-band data exfiltration, blind XXE, and WAF bypass — with payloads you can use in your next pentest. ...

Server-Side Request Forgery (SSRF) is one of the most dangerous and consistently exploited web vulnerabilities of the last five years. It made the OWASP Top 10 in 2021 and has been weaponized in some of the biggest breaches in cloud history — including the Capital One breach that exposed 100 million records. If you’re doing web application pentesting or bug bounty hunting in 2026 and you’re not hunting SSRF systematically, you’re leaving money and flags on the table. ...

Cross-site request forgery is one of those vulnerabilities that sounds simple until you actually try to exploit it in a modern application. In theory: trick a user’s browser into making an authenticated request to a target site. In practice: CSRF token validation, SameSite cookie policies, and Referer checks have made it significantly harder — but not impossible. In 2026, pure CSRF is less common on major platforms, but it still shows up regularly in internal tools, legacy enterprise apps, custom-built APIs, and any application that implements CSRF protection carelessly. And when CSRF tokens are present but misconfigured, the bypass is often trivially easy. ...

Cross-site scripting has been broken for as long as the web has existed. In 2026, it still shows up everywhere — modern SPAs, legacy enterprise apps, AI-generated frontends with no output encoding, CMS platforms with half-baked sanitization. XSS is the kind of vulnerability that’s “easy” to dismiss until you see a session token extracted from a banking app or a phishing payload delivered from a trusted domain. This guide covers everything: how XSS works, the three main categories, detection with Burp and manual techniques, exploitation for real impact, filter bypass when WAFs and sanitizers are in the way, and DOM-based XSS which most people still get wrong. ...