This post was updated on January 20, 2026. On October 13, 2025, security researchers from FearsOff identified and reported a vulnerability in Cloudflare’s ACME (Automatic Certificate Management Environment) validation logic that disabled some of the WAF features on specific ACME-related paths. The vulnerability was reported and validated through Cloudflare’s bug bounty program. The vulnerability was […]
Tag Archives: waf
Cloudflare WAF proactively protects against React vulnerability
Cloudflare has deployed a new protection to address a vulnerability in React Server Components (RSC). All Cloudflare customers are automatically protected, including those on free and paid plans, as long as their React application traffic is proxied through the Cloudflare Web Application Firewall (WAF). Cloudflare Workers are inherently immune to this exploit. React-based applications and […]
Get better visibility for the WAF with payload logging
As the surface area for attacks on the web increases, Cloudflare’s Web Application Firewall (WAF) provides a myriad of solutions to mitigate these attacks. This is great for our customers, but the cardinality in the workloads of the millions of requests we service means that generating false positives is inevitable. This means that the default […]
One IP address, many users: detecting CGNAT to reduce collateral effects
IP addresses have historically been treated as stable identifiers for non-routing purposes such as for geolocation and security operations. Many operational and security mechanisms, such as blocklists, rate-limiting, and anomaly detection, rely on the assumption that a single IP address represents a cohesive, accountable entity or even, possibly, a specific user or device. But the […]
Block unsafe prompts targeting your LLM endpoints with Firewall for AI
Security teams are racing to secure a new attack surface: AI-powered applications. From chatbots to search assistants, LLMs are already shaping customer experience, but they also open the door to new risks. A single malicious prompt can exfiltrate sensitive data, poison a model, or inject toxic content into customer-facing interactions, undermining user trust. Without guardrails, […]
Cloudflare protects against critical SharePoint vulnerability, CVE-2025-53770
On July 19, 2025, Microsoft disclosed CVE-2025-53770, a critical zero-day Remote Code Execution (RCE) vulnerability. Assigned a CVSS 3.1 base score of 9.8 (Critical), the vulnerability affects SharePoint Server 2016, 2019, and the Subscription Edition, along with unsupported 2010 and 2013 versions. Cloudflare’s WAF Managed Rules now includes 2 emergency releases that mitigate these vulnerabilities […]
Cloudflare named a leader in Web Application Firewall Solutions in 2025 Forrester report
Forrester Research has recognized Cloudflare as a Leader in its The Forrester Wave™: Web Application Firewall Solutions, Q1 2025 report. This market analysis helps security and risk professionals select the right solution for their needs. According to Forrester: “Cloudflare is a strong option for customers that want to manage an easy-to-use, unified web application protection […]
Introducing Cloudy, Cloudflare’s AI agent for simplifying complex configurations
It’s a big day here at Cloudflare! Not only is it Security Week, but today marks Cloudflare’s first step into a completely new area of functionality, intended to improve how our users both interact with, and get value from, all of our products. We’re excited to share a first glance of how we’re embedding AI […]
Making Application Security simple with a new unified dashboard experience
Over the years, we have framed our Application Security features against market-defined product groupings such as Web Application Firewall (WAF), DDoS Mitigation, Bot Management, API Security (API Shield), Client Side Security (Page Shield), and so forth. This has led to unnecessary artificial separation of what is, under the hood, a well-integrated single platform. This separation, […]
Resolving a Mutual TLS session resumption vulnerability
On January 23, 2025, Cloudflare was notified via its Bug Bounty Program of a vulnerability in Cloudflare’s Mutual TLS (mTLS) implementation. The vulnerability affected customers who were using mTLS and involved a flaw in our session resumption handling. Cloudflare’s investigation revealed no evidence that the vulnerability was being actively exploited. And tracked as CVE-2025-23419, Cloudflare […]
