CVE-2026-27696: SSRF in changedetection.io via URL Validation Bypass

A high-severity SSRF vulnerability (CVSS 8.6) was disclosed on February 25, 2026 in changedetection.io, a popular open-source tool for monitoring web page changes. The bug is a textbook example of a failed allowlist/denylist approach to URL validation — and the default unauthenticated configuration makes it exploitable by anyone with network access to the instance. What is changedetection.io? changedetection.io is a self-hosted service that watches URLs for content changes and alerts you when something changes. It’s commonly used by developers, researchers, and sysadmins to monitor pages, APIs, and dashboards. The tool fetches URLs on your behalf — which is exactly the trust relationship SSRF attacks exploit. ...

February 27, 2026 · 3 min · Carl Sampson

Writing Secure Python Applications: Preventing SSRF, SQL Injection, and XSS

1. Core Security Foundations Treat all input as untrusted. Validate strictly (whitelists over blacklists), normalize before checks, and enforce types and sizes. Use framework security features instead of writing your own. Least privilege: minimize DB, filesystem, and network permissions. Secrets management: use environment variables or secret stores, never hardcode. Dependency hygiene: pin and audit dependencies with pip-audit or Safety. Secure HTTP headers: add HSTS, X-Frame-Options, CSP, and others. Logging & monitoring: log relevant events, but never credentials. Testing: integrate Bandit and Semgrep in CI. 2. Preventing SQL Injection (SQLi) Principle: Never build queries using string concatenation. ...

November 3, 2025 · 3 min · Carl Sampson

Exploring SSRF Attack Vectors: Understanding the Threat

Server-Side Request Forgery (SSRF) is a type of security vulnerability that allows an attacker to send crafted requests from a vulnerable server to internal or external resources. This can lead to unauthorized access to sensitive data, manipulation of server behavior, or even exploitation of other services within the network. SSRF exploits the trust that a server has in its own requests, allowing attackers to leverage this trust to perform actions that would typically be restricted. ...

May 12, 2025 · 7 min · chs

SSRF Defense

Defending Your Web Applications Against Server-Side Request Forgery (SSRF) Attacks In today’s interconnected digital landscape, web applications face a myriad of security threats. One often overlooked but potentially devastating vulnerability is Server-Side Request Forgery (SSRF). Did you know that, according to a recent report, SSRF attacks have increased by a staggering 270% in the past year alone? In this blog post, we’ll dive into what SSRF is, how it can impact your web applications, and most importantly, the steps you can take to defend against these insidious attacks. ...

April 28, 2025 · 3 min · chs