Emergency WAF rules for CVE-2025-55183 and CVE-2025-55184
Emergency security release adding WAF rules to protect against server-side function exposure (CVE-2025-55183) and React function denial-of-service attacks (CVE-2025-55184). These rules block or flag malicious patterns that could expose internal application logic or disrupt service availability.
This emergency release introduces rules for CVE-2025-55183 and CVE-2025-55184, targeting server-side function exposure and resource-exhaustion patterns, respectively.
Key Findings
Added coverage for Leaking Server Functions (CVE-2025-55183) and React Function DoS detection (CVE-2025-55184).
Impact
These updates strengthen protection for server-function abuse techniques (CVE-2025-55183, CVE-2025-55184) that may expose internal logic or disrupt application availability.
| Ruleset | Rule ID | Legacy Rule ID | Description | Previous Action | New Action | Comments |
|---|---|---|---|---|---|---|
| Cloudflare Managed Ruleset | ...fefb4e9b | N/A | React - Leaking Server Functions - CVE:CVE-2025-55183 | N/A | Block | This was labeled as Generic - Server Function Source Code Exposure. |
| Cloudflare Free Ruleset | ...251e86aa | N/A | React - Leaking Server Functions - CVE:CVE-2025-55183 | N/A | Block | This was labeled as Generic - Server Function Source Code Exposure. |
| Cloudflare Managed Ruleset | ...102ec699 | N/A | React - DoS - CVE:CVE-2025-55184 | N/A | Disabled | This was labeled as Generic – Server Function Resource Exhaustion. |
Source: original entry ↗
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