Changelog

This emergency release adds a new managed rule to block active exploitation of a critical remote code execution (RCE) and SQL injection (SQLi) vulnerability found in popular web frameworks.

Key Findings

• Generic Frameworks - Unauthenticated RCE: Attackers can execute arbitrary system commands with web server privileges by sending malicious input containing invalid path sequences during request processing.

• Generic Frameworks - SQLi: Attackers can execute unauthorized database queries due to a failure to sanitize input values within request parameters.

This release introduces new rules targeting critical infrastructure vulnerabilities. These include an unauthenticated memory disclosure flaw in Citrix NetScaler ADC and Gateway (CVE-2026-8451) and a high-severity pre-authentication remote code execution (RCE) vulnerability in Progress Kemp LoadMaster (CVE-2026-8037).

Key Findings

• CVE-2026-8451: An insufficient input validation vulnerability affects Citrix NetScaler ADC and NetScaler Gateway appliances configured as a SAML Identity Provider (IdP). Remote, unauthenticated attackers can exploit this flaw by sending malformed requests to trigger a memory overread, allowing them to leak chunks of sensitive data from adjacent appliance memory.

• CVE-2026-8037: A critical OS command injection vulnerability in Progress Kemp LoadMaster load balancers allows unauthenticated remote attackers to achieve remote code execution (RCE).

This release adds targeted coverage for a path traversal flaw in Fortinet FortiSandbox (CVE-2026-39813) and transitions the Anomaly:Header:User-Agent - Fake Bing or MSN Bot rule action from Block to Disabled.

Key Findings

• CVE-2026-39813: A path traversal vulnerability in Fortinet FortiSandbox allows remote, unauthenticated attackers to read arbitrary files from the underlying filesystem due to insufficient validation of user-supplied input paths.

This week's release introduces new managed protection to address a critical pre-authentication OS command injection vulnerability in Ivanti Sentry (CVE-2026-10520).

Key Findings

• CVE-2026-10520: An OS command injection vulnerability in Ivanti Sentry allows remote, unauthenticated attackers to execute arbitrary system commands with root privileges. The flaw stems from improper sanitization of input strings parsed during internal configuration handling.

You can now match incoming requests against Cloudforce One threat intelligence in your WAF rules. A new detection looks up the client IP address of each request against the threat intelligence database. If the IP was involved in threat activity in the past seven days, Cloudflare populates cf.intel.ip.* fields that you can use in custom rules and rate limiting rules.

The detection populates the following fields. Use the any() function with the [*] wildcard to match array values:

• cf.intel.ip.datasets — the dataset that flagged the IP address (ddos or waf).
• cf.intel.ip.target_industries — industries the IP address has targeted.
• cf.intel.ip.attacker_names — known threat actors associated with the IP address.
• cf.intel.ip.attacker_countries — source countries of the threat activity.
• cf.intel.ip.target_countries — countries the IP address has targeted.

For example, the following custom rule expression blocks requests from IP addresses associated with DDoS activity that have targeted France:

any(cf.intel.ip.target_countries[*] == "FR") and any(cf.intel.ip.datasets[*] == "ddos")

These fields work with the Cloudflare API and Terraform. Matches are logged in Security Analytics.

The threat intelligence detection is available to customers with an active Cloudforce One subscription. For more information, refer to Threat intelligence.

This week's release introduces new managed protection to address a critical SQL injection vulnerability in Ghost CMS (CVE-2026-26980) and a new generic rule designed to identify and block sophisticated SQL Injection (SQLi) bypass attempts leveraging obfuscated boolean logic. These rules protect affected installations from unauthorized data exfiltration at the network edge.

Key Findings

• CVE-2026-26980: A blind SQL injection vulnerability in the Ghost CMS Content API (versions 3.24.0 to 6.19.0) allows unauthenticated remote attackers to inject malicious SQL commands via query parameters due to improper input validation.

This release introduces new detections for a critical SQL injection vulnerability in Drupal installations utilizing PostgreSQL (CVE-2026-9082), alongside targeted protection for an unsafe deserialization flaw in the Mirasvit Cache Warmer extension (CVE-2026-45247). Additionally, this release includes coverage for a prototype pollution vector in Axios (CVE-2026-40175) and a new generic rule designed to identify and block sophisticated SQL Injection (SQLi) bypass attempts leveraging obfuscated boolean logic.

Key Findings

• CVE-2026-9082: A database abstraction vulnerability affects Drupal sites configured with a PostgreSQL backend. Remote, unauthenticated attackers can exploit this flaw via crafted inputs to inject malicious SQL commands and access or manipulate backend data.

• CVE-2026-45247: A PHP Object Injection vulnerability exists in the Mirasvit Cache Warmer extension for Magento and Adobe Commerce. This flaw stems from unsafe deserialization of untrusted user input, enabling unauthenticated attackers to execute arbitrary code on the hosting server.

• CVE-2026-40175: A prototype pollution vulnerability affects the Axios HTTP client library. Attackers can exploit this to inject malicious properties into the global JavaScript object prototype, potentially causing application crashes (Denial of Service) or executing unauthorized code depending on the application structure.

Impact

Successful exploitation of these vulnerabilities could allow unauthenticated attackers to execute arbitrary code, manipulate database contents, or induce application crashes, leading to severe operational disruption or complete server compromise. These newly deployed signatures intercept these advanced malicious payloads at the edge before they can interact with vulnerable software configurations.

Key Findings

• Existing rule enhancements have been deployed to improve detection resilience against broad classes of web attacks and strengthen behavioral coverage.

Continuous Rule Improvements

We are continuously refining our managed rules to provide more resilient protection and deeper insights into attack patterns. To ensure an optimal security posture, we recommend consistently monitoring the Security Events dashboard and adjusting rule actions as these enhancements are deployed.

This emergency release introduces two new rules to detect nginx heap buffer overflow and heap spray exploitation attempts targeting the rewrite module's is_args stale-state bug (CVE-2026-42945).

Key Findings

CVE-2026-42945: nginx Heap Buffer Overflow via Stale is_args in Rewrite Module

Successful exploitation allows remote attackers to trigger a heap buffer overflow in nginx's rewrite module by sending crafted URIs containing escapable characters. A length/copy pass mismatch in ngx_http_script_copy_capture_code() causes the copy pass to write escaped data into an undersized buffer, leading to heap corruption. This enables denial of service (worker process crash) and, with heap feng shui techniques, potential remote code execution.

We strongly recommend upgrading to nginx 1.30.1 (or later) immediately to address the underlying vulnerability. If you cannot upgrade immediately, avoid rewrite directives with ? in the replacement string followed by set or if referencing capture groups.

Key Findings

• Existing rule enhancements have been deployed to improve detection resilience against broad classes of web attacks and strengthen behavioral coverage.

Continuous Rule Improvements

We are continuously refining our managed rules to provide more resilient protection and deeper insights into attack patterns. To ensure an optimal security posture, we recommend consistently monitoring the Security Events dashboard and adjusting rule actions as these enhancements are deployed.

Multiple security vulnerabilities were disclosed by the React team and Vercel affecting React Server Components and Next.js. These include denial of service, middleware and proxy bypass, server-side request forgery, cross-site scripting, and cache poisoning issues across a range of severity levels.

We strongly recommend updating your application and its dependencies immediately. Patched versions are available for React (react-server-dom-webpack, react-server-dom-parcel, and react-server-dom-turbopack 19.0.6, 19.1.7, and 19.2.6) and Next.js (15.5.16 and 16.2.5).

Cloudflare WAF rules deployed in response to prior React Server Component CVEs (CVE-2025-55184 ↗ and CVE-2026-23864 ↗) already provide coverage for the newly disclosed denial-of-service vulnerabilities. These rules are enabled by default with a Block action for all customers using the Cloudflare Managed Ruleset, including Free plan customers using the Free Managed Ruleset.

The existing rules detect the underlying attack patterns generically. As a result, they apply to the new CVE-2026-23870 ↗ denial-of-service vulnerability in Server Components and the corresponding Next.js advisory GHSA-8h8q-6873-q5fj ↗.

Cloudflare is investigating whether WAF rules can be safely and effectively deployed for three of the high-severity advisories: CVE-2026-23870 ↗ / GHSA-8h8q-6873-q5fj ↗, GHSA-267c-6grr-h53f ↗, and GHSA-mg66-mrh9-m8jx ↗. If it is possible to create a managed WAF rule that mitigates these CVEs and does not potentially break application behavior, Cloudflare will add additional managed WAF rules. These rules will be announced through the WAF changelog. Because these vulnerabilities were shared with Cloudflare with minimal advance notice, we are still investigating what WAF mitigations are possible.

Several of the disclosed vulnerabilities are not possible to block in WAF. We strongly recommend updating your applications so they are not purely reliant on WAF mitigations.

Customers on Pro, Business, or Enterprise plans should ensure that Managed Rules are enabled.

Vinext: Vinext ↗ is a Vite plugin that reimplements the Next.js API surface. Vinext's latest release is not vulnerable to any of the disclosed CVEs. Vinext's architecture differs from stock Next.js in ways that sidestep the affected code paths. For example, it does not implement the PPR resume protocol, does not expose Pages Router data-route endpoints, and strips internal headers such as x-nextjs-data at request boundaries. As an extra layer of defense, we added a React 19.2.6 or later requirement when running vinext init (PR #1118 ↗, PR #1112 ↗) to prevent accidentally running a vulnerable version of React with Vinext.

OpenNext on Cloudflare: OpenNext is an adapter that lets you deploy Next.js apps to the Cloudflare Workers platform. OpenNext itself is not directly vulnerable to the React denial-of-service CVE, but users must update the Next.js version in their application. The OpenNext team has updated the adapter to further harden against these vectors and released a new version of the Cloudflare adapter. Test fixtures and examples have been updated to use patched versions (PR #1255 ↗).

This emergency release introduces a new rule to detect Next.js App Router middleware and proxy bypass attempts via segment-prefetch routes (CVE-2026-44575).

Key Findings

CVE-2026-44575: Next.js Middleware / Proxy Bypass in App Router Applications via Segment-Prefetch Routes

Successful exploitation allows unauthenticated attackers to bypass middleware or proxy-based authorization checks in affected Next.js App Router applications. This leads to unauthorized access to protected content, potential exposure of sensitive application data, and compromise of application security boundaries.

We strongly recommend upgrading to Next.js 15.5.16 or 16.2.5 (or later) immediately to address the underlying vulnerability. If you cannot upgrade immediately, enforce authorization in the underlying route or page logic instead of relying solely on middleware.

This week's release focuses on new detections to expand coverage across command injection, SQL injection, PHP object injection, remote code execution, and XSS attack vectors.

Key Findings

• Existing rule enhancements have been deployed to improve detection resilience against broad classes of web attacks and strengthen behavioral coverage.

Continuous Rule Improvements

We are continuously refining our managed rules to provide more resilient protection and deeper insights into attack patterns. To ensure an optimal security posture, we recommend consistently monitoring the Security Events dashboard and adjusting rule actions as these enhancements are deployed.

This emergency release introduces a new rule to block a cPanel & WHM Authentication Bypass related to CVE-2026-41940.

Key Findings

• CVE-2026-41940: A critical authentication bypass vulnerability in cPanel & WHM allows unauthenticated remote attackers to bypass authentication mechanisms and gain unauthorized administrative access to the web hosting control panel. This vulnerability affects the session validation logic, enabling attackers to craft malicious requests that circumvent normal authentication checks.

Impact

Successful exploitation allows unauthenticated attackers to gain administrative control over affected cPanel & WHM installations. This leads to complete server compromise, potential theft or manipulation of hosted data, and significant service disruption across managed environments.

We strongly recommend applying official vendor patches for cPanel & WHM immediately to address the underlying vulnerability.

This week's release focuses on new improvements to enhance coverage.

Key Findings

• Existing rule enhancements have been deployed to improve detection resilience against broad classes of web attacks and strengthen behavioral coverage.

Continuous Rule Improvements

We are continuously refining our managed rules to provide more resilient protection and deeper insights into attack patterns. To ensure an optimal security posture, we recommend consistently monitoring the Security Events dashboard and adjusting rule actions as these enhancements are deployed.

This week's release introduces a new detection for a Remote Code Execution (RCE) vulnerability in Apache ActiveMQ (CVE-2026-34197) and an updated signature for Magento 2 - Unrestricted File Upload. Alongside these detections, we are continuing our work on rule refinements to provide deeper security insights for our customers.

Key Findings

• Apache ActiveMQ (CVE-2026-34197): A vulnerability in Apache ActiveMQ allows an unauthenticated, remote attacker to execute arbitrary code. This flaw occurs during the processing of specially crafted network packets, leading to potential full system compromise.

• Magento 2 - Unrestricted File Upload - 2: This is a follow-up enhancement to our existing protections for Magento and Adobe Commerce.

Impact

Successful exploitation of these vulnerabilities could allow unauthenticated attackers to execute arbitrary code or gain full administrative control over affected servers. We strongly recommend applying official vendor patches for Apache ActiveMQ and Magento to address the underlying vulnerabilities.

Continuous Rule Improvements

We are continuously refining our managed rules to provide more resilient protection and deeper insights into attack patterns. To ensure an optimal security posture, we recommend consistently monitoring the Security Events dashboard and adjusting rule actions as these enhancements are deployed.

This week's release introduces a new detection for a critical Remote Code Execution (RCE) vulnerability in Mesop (CVE-2026-33057), alongside protections for high-impact vulnerabilities in Cisco Secure Firewall Management Center (CVE-2026-20079) and FortiClient EMS (CVE-2026-21643). Additionally, this release includes an update to our existing React Server DoS coverage to address recently identified resource exhaustion vectors (CVE-2026-23869).

Key Findings

• Cisco Secure FMC (CVE-2026-20079): A vulnerability in the web-based management interface of Cisco Secure Firewall Management Center (FMC) that allows an unauthenticated, remote attacker to execute arbitrary commands or bypass security filters.

• FortiClient EMS (CVE-2026-21643): A critical vulnerability in the FortiClient EMS permitting unauthorized access or administrative configuration manipulation via crafted HTTP requests.

• Mesop (CVE-2026-33057): A vulnerability in the Mesop Python-based UI framework where unauthenticated attackers can execute arbitrary code by sending specially crafted, Base64-encoded payloads in the request body.

Impact

Successful exploitation of these vulnerabilities could allow unauthenticated attackers to execute arbitrary code, gain administrative control over network management infrastructure, or trigger server-side resource exhaustion. Administrators are strongly encouraged to apply official vendor updates.

The decode script injected by Email Address Obfuscation now loads with the defer attribute. This means the script no longer blocks page rendering. It downloads in parallel with HTML parsing and executes after the document is fully parsed, before the DOMContentLoaded event.

This improves page loading performance, contributing to better Core Web Vitals, for all zones with Email Address Obfuscation on. No action is required.

If you have custom JavaScript that depends on email addresses being decoded at a specific point during page load, note that the decode script now executes after HTML parsing completes rather than inline during parsing.

This week's release introduces new detections for a critical Remote Code Execution (RCE) vulnerability in MCP Server (CVE-2026-23744), alongside targeted protection for an authentication bypass vulnerability in SolarWinds products (CVE-2025-40552). Additionally, this release includes a new generic detection rule designed to identify and block Cross-Site Scripting (XSS) injection attempts leveraging "OnEvent" handlers within HTTP cookies.

Key Findings

• MCP Server (CVE-2026-23744): A vulnerability in the Model Context Protocol (MCP) server implementation where malformed input payloads can trigger a memory corruption state, allowing for arbitrary code execution.

• SolarWinds (CVE-2025-40552): A critical flaw in the authentication module allows unauthenticated attackers to bypass security filters and gain unauthorized access to the management console due to improper identity token validation.

• XSS OnEvents Cookies: This generic rule identifies malicious event handlers (such as onload or onerror) embedded within HTTP cookie values.

Impact

Successful exploitation of the MCP Server and SolarWinds vulnerabilities could allow unauthenticated attackers to execute arbitrary code or gain administrative control, leading to a full system takeover. Additionally, the new generic XSS detection prevents attackers from leveraging browser event handlers in cookies to hijack user sessions or execute malicious scripts.

This week's release introduces new detections for a critical authentication bypass vulnerability in Fortinet products (CVE-2025-59718), alongside three new generic detection rules designed to identify and block HTTP Parameter Pollution attempts. Additionally, this release includes targeted protection for a high-impact unrestricted file upload vulnerability in Magento and Adobe Commerce.

Key Findings

• CVE-2025-59718: An improper cryptographic signature verification vulnerability in Fortinet FortiOS, FortiProxy, and FortiSwitchManager. This may allow an unauthenticated attacker to bypass the FortiCloud SSO login authentication using a maliciously crafted SAML message, if that feature is enabled on the device.

• Magento 2 - Unrestricted File Upload: A critical flaw in Magento and Adobe Commerce allows unauthenticated attackers to bypass security checks and upload malicious files to the server, potentially leading to Remote Code Execution (RCE).

Impact

Successful exploitation of the Fortinet and Magento vulnerabilities could allow unauthenticated attackers to gain administrative control or deploy webshells, leading to complete server compromise and data theft.

This week's release focuses on new improvements to enhance coverage.

Key Findings

• Existing rule enhancements have been deployed to improve detection resilience against broad classes of web attacks and strengthen behavioral coverage.

This week's release introduces new detections for vulnerabilities in Ivanti Endpoint Manager Mobile (CVE-2026-1281 and CVE-2026-1340), alongside a new generic detection rule designed to identify and block Cross-Site Scripting (XSS) injection attempts within the Content-Security-Policy (CSP) HTTP request header.

Key Findings

• CVE-2026-1281 & CVE-2026-1340: Ivanti Endpoint Manager Mobile processes HTTP requests through Apache RevwriteMap directives that pass user-controlled input to Bash scripts (/mi/bin/map-appstore-url and /mi/bin/map-aft-store-url). Bash scripts do not sanitize user input and are vulnerable to shell arithmetic expansion thereby allowing attackers to achieve unauthenticated remote code execution.
• Generic XSS in CSP Header: This rule identifies malicious payloads embedded within the request's Content-Security-Policy header. It specifically targets scenarios where web frameworks or applications trust and extract values directly from the CSP header in the incoming request without sufficient validation. Attackers can provide crafted header values to inject scripts or malicious directives that are subsequently processed by the server.

Impact

Successful exploitation of Ivanti EPMM vulnerability allows unauthenticated remote code execution and generic XSS in CSP header allows attackers to inject malicious scripts during page rendering. In environments using server-side caching, this poisoned XSS content can subsequently be cached and automatically served to all visitors.

This week's release introduces new detections for vulnerabilities in SmarterTools SmarterMail (CVE-2025-52691 and CVE-2026-23760), alongside improvements to an existing Command Injection (nslookup) detection to enhance coverage.

Key Findings

• CVE-2025-52691: SmarterTools SmarterMail mail server is vulnerable to Arbitrary File Upload, allowing an unauthenticated attacker to upload files to any location on the mail server, potentially enabling remote code execution.
• CVE-2026-23760: SmarterTools SmarterMail versions prior to build 9511 contain an authentication bypass vulnerability in the password reset API permitting unaunthenticated to reset system administrator accounts failing to verify existing password or reset token.

Impact

Successful exploitation of these SmarterMail vulnerabilities could lead to full system compromise or unauthorized administrative access to mail servers. Administrators are strongly encouraged to apply vendor patches without delay.

This week’s release introduces new detections for CVE-2025-68645 and CVE-2025-31125.

Key Findings

• CVE-2025-68645: A Local File Inclusion (LFI) vulnerability in the Webmail Classic UI of Zimbra Collaboration Suite (ZCS) 10.0 and 10.1 allows unauthenticated remote attackers to craft requests to the /h/rest endpoint, improperly influence internal dispatching, and include arbitrary files from the WebRoot directory.
• CVE-2025-31125: Vite, the JavaScript frontend tooling framework, exposes content of non-allowed files via ?inline&import when its development server is network-exposed, enabling unauthorized attackers to read arbitrary files and potentially leak sensitive information.