diff --git a/src/agents/tools/web-fetch.ts b/src/agents/tools/web-fetch.ts
index 92f94bf3a28..c9823726f2e 100644
--- a/src/agents/tools/web-fetch.ts
+++ b/src/agents/tools/web-fetch.ts
@@ -458,6 +458,9 @@ type WebFetchRuntimeParams = FirecrawlRuntimeParams & {
   cacheTtlMs: number;
   userAgent: string;
   readabilityEnabled: boolean;
+  ssrfPolicy?: {
+    allowRfc2544BenchmarkRange?: boolean;
+  };
 };
 
 function toFirecrawlContentParams(
@@ -512,8 +515,10 @@ async function maybeFetchFirecrawlWebFetchPayload(
 }
 
 async function runWebFetch(params: WebFetchRuntimeParams): Promise<Record<string, unknown>> {
+  // Include ssrfPolicy in cache key to prevent cross-policy cache bypass
+  const ssrfPolicySuffix = params.ssrfPolicy?.allowRfc2544BenchmarkRange ? ":rfc2544" : "";
   const cacheKey = normalizeCacheKey(
-    `fetch:${params.url}:${params.extractMode}:${params.maxChars}`,
+    `fetch:${params.url}:${params.extractMode}:${params.maxChars}${ssrfPolicySuffix}`,
   );
   const cached = readCache(FETCH_CACHE, cacheKey);
   if (cached) {
@@ -534,11 +539,18 @@ async function runWebFetch(params: WebFetchRuntimeParams): Promise<Record<string
   let res: Response;
   let release: (() => Promise<void>) | null = null;
   let finalUrl = params.url;
+  
+  // Build SSRF policy from config
+  const policy = params.ssrfPolicy?.allowRfc2544BenchmarkRange
+    ? { allowRfc2544BenchmarkRange: true }
+    : undefined;
+  
   try {
     const result = await fetchWithWebToolsNetworkGuard({
       url: params.url,
       maxRedirects: params.maxRedirects,
       timeoutSeconds: params.timeoutSeconds,
+      policy,
       init: {
         headers: {
           Accept: "text/markdown, text/html;q=0.9, */*;q=0.1",
@@ -741,6 +753,7 @@ export function createWebFetchTool(options?: {
     return null;
   }
   const readabilityEnabled = resolveFetchReadabilityEnabled(fetch);
+  const ssrfPolicy = fetch?.ssrfPolicy;
   const firecrawl = resolveFirecrawlConfig(fetch);
   const runtimeFirecrawlActive = options?.runtimeFirecrawl?.active;
   const shouldResolveFirecrawlApiKey =
@@ -787,6 +800,7 @@ export function createWebFetchTool(options?: {
         cacheTtlMs: resolveCacheTtlMs(fetch?.cacheTtlMinutes, DEFAULT_CACHE_TTL_MINUTES),
         userAgent,
         readabilityEnabled,
+        ssrfPolicy,
         firecrawlEnabled,
         firecrawlApiKey,
         firecrawlBaseUrl,
diff --git a/src/config/types.tools.ts b/src/config/types.tools.ts
index f42fa365f6f..adad35ce083 100644
--- a/src/config/types.tools.ts
+++ b/src/config/types.tools.ts
@@ -505,6 +505,11 @@ export type ToolsConfig = {
       userAgent?: string;
       /** Use Readability to extract main content (default: true). */
       readability?: boolean;
+      /** SSRF policy configuration for web_fetch. */
+      ssrfPolicy?: {
+        /** Allow RFC 2544 benchmark range IPs (198.18.0.0/15) for fake-IP proxy compatibility (e.g., Clash TUN mode, Surge). */
+        allowRfc2544BenchmarkRange?: boolean;
+      };
       firecrawl?: {
         /** Enable Firecrawl fallback (default: true when apiKey is set). */
         enabled?: boolean;
diff --git a/src/config/zod-schema.agent-runtime.ts b/src/config/zod-schema.agent-runtime.ts
index 10f0f8637e9..775d619b92f 100644
--- a/src/config/zod-schema.agent-runtime.ts
+++ b/src/config/zod-schema.agent-runtime.ts
@@ -332,6 +332,12 @@ export const ToolsWebFetchSchema = z
     maxRedirects: z.number().int().nonnegative().optional(),
     userAgent: z.string().optional(),
     readability: z.boolean().optional(),
+    ssrfPolicy: z
+      .object({
+        allowRfc2544BenchmarkRange: z.boolean().optional(),
+      })
+      .strict()
+      .optional(),
     firecrawl: z
       .object({
         enabled: z.boolean().optional(),