diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6a3720385..e2e552ef8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -25,6 +25,7 @@ Docs: https://docs.openclaw.ai
 - Security/Discord: add `openclaw security audit` warnings for name/tag-based Discord allowlist entries (DM allowlists, guild/channel `users`, and pairing-store entries), highlighting slug-collision risk while keeping name-based matching supported, and canonicalize resolved Discord allowlist names to IDs at runtime without rewriting config files. Thanks @tdjackey for reporting.
 - Security/Gateway: block node-role connections when device identity metadata is missing.
 - Security/Media: enforce inbound media byte limits during download/read across Discord, Telegram, Zalo, Microsoft Teams, and BlueBubbles to prevent oversized payload memory spikes before rejection. This ships in the next npm release. Thanks @tdjackey for reporting.
+- Security/MSTeams media: enforce allowlist checks for SharePoint reference attachment URLs and redirect targets during Graph-backed media fetches so redirect chains cannot escape configured media host boundaries. This ships in the next npm release. Thanks @tdjackey for reporting.
 - Chat/Usage/TUI: strip synthetic inbound metadata blocks (including `Conversation info` and trailing `Untrusted context` channel metadata wrappers) from displayed conversation history so internal prompt context no longer leaks into user-visible logs.
 - Security/Browser relay: harden extension relay auth token handling for `/extension` and `/cdp` pathways.
 - Cron: persist `delivered` state in cron job records so delivery failures remain visible in status and logs. (#19174) Thanks @simonemacario.
diff --git a/extensions/msteams/src/attachments.test.ts b/extensions/msteams/src/attachments.test.ts
index 36a664714..be7251979 100644
--- a/extensions/msteams/src/attachments.test.ts
+++ b/extensions/msteams/src/attachments.test.ts
@@ -459,6 +459,88 @@ describe("msteams attachments", () => {
 
       expect(media.media).toHaveLength(2);
     });
+
+    it("blocks SharePoint redirects to hosts outside allowHosts", async () => {
+      const { downloadMSTeamsGraphMedia } = await load();
+      const shareUrl = "https://contoso.sharepoint.com/site/file";
+      const escapedUrl = "https://evil.example/internal.pdf";
+      fetchRemoteMediaMock.mockImplementationOnce(async (params) => {
+        const fetchFn = params.fetchImpl ?? fetch;
+        let currentUrl = params.url;
+        for (let i = 0; i < 5; i += 1) {
+          const res = await fetchFn(currentUrl, { redirect: "manual" });
+          if ([301, 302, 303, 307, 308].includes(res.status)) {
+            const location = res.headers.get("location");
+            if (!location) {
+              throw new Error("redirect missing location");
+            }
+            currentUrl = new URL(location, currentUrl).toString();
+            continue;
+          }
+          if (!res.ok) {
+            throw new Error(`HTTP ${res.status}`);
+          }
+          return {
+            buffer: Buffer.from(await res.arrayBuffer()),
+            contentType: res.headers.get("content-type") ?? undefined,
+            fileName: params.filePathHint,
+          };
+        }
+        throw new Error("too many redirects");
+      });
+
+      const fetchMock = vi.fn(async (url: string) => {
+        if (url.endsWith("/hostedContents")) {
+          return new Response(JSON.stringify({ value: [] }), { status: 200 });
+        }
+        if (url.endsWith("/attachments")) {
+          return new Response(JSON.stringify({ value: [] }), { status: 200 });
+        }
+        if (url.endsWith("/messages/123")) {
+          return new Response(
+            JSON.stringify({
+              attachments: [
+                {
+                  id: "ref-1",
+                  contentType: "reference",
+                  contentUrl: shareUrl,
+                  name: "report.pdf",
+                },
+              ],
+            }),
+            { status: 200 },
+          );
+        }
+        if (url.startsWith("https://graph.microsoft.com/v1.0/shares/")) {
+          return new Response(null, {
+            status: 302,
+            headers: { location: escapedUrl },
+          });
+        }
+        if (url === escapedUrl) {
+          return new Response(Buffer.from("should-not-be-fetched"), {
+            status: 200,
+            headers: { "content-type": "application/pdf" },
+          });
+        }
+        return new Response("not found", { status: 404 });
+      });
+
+      const media = await downloadMSTeamsGraphMedia({
+        messageUrl: "https://graph.microsoft.com/v1.0/chats/19%3Achat/messages/123",
+        tokenProvider: { getAccessToken: vi.fn(async () => "token") },
+        maxBytes: 1024 * 1024,
+        allowHosts: ["graph.microsoft.com", "contoso.sharepoint.com"],
+        fetchFn: fetchMock as unknown as typeof fetch,
+      });
+
+      expect(media.media).toHaveLength(0);
+      const calledUrls = fetchMock.mock.calls.map((call) => String(call[0]));
+      expect(
+        calledUrls.some((url) => url.startsWith("https://graph.microsoft.com/v1.0/shares/")),
+      ).toBe(true);
+      expect(calledUrls).not.toContain(escapedUrl);
+    });
   });
 
   describe("buildMSTeamsMediaPayload", () => {
diff --git a/extensions/msteams/src/attachments/graph.ts b/extensions/msteams/src/attachments/graph.ts
index 7ac94887d..5303246de 100644
--- a/extensions/msteams/src/attachments/graph.ts
+++ b/extensions/msteams/src/attachments/graph.ts
@@ -5,6 +5,7 @@ import {
   GRAPH_ROOT,
   inferPlaceholder,
   isRecord,
+  isUrlAllowed,
   normalizeContentType,
   resolveRequestUrl,
   resolveAllowedHosts,
@@ -31,6 +32,25 @@ type GraphAttachment = {
   content?: unknown;
 };
 
+function isRedirectStatus(status: number): boolean {
+  return [301, 302, 303, 307, 308].includes(status);
+}
+
+function readRedirectUrl(baseUrl: string, res: Response): string | null {
+  if (!isRedirectStatus(res.status)) {
+    return null;
+  }
+  const location = res.headers.get("location");
+  if (!location) {
+    return null;
+  }
+  try {
+    return new URL(location, baseUrl).toString();
+  } catch {
+    return null;
+  }
+}
+
 function readNestedString(value: unknown, keys: Array<string | number>): string | undefined {
   let current: unknown = value;
   for (const key of keys) {
@@ -264,6 +284,9 @@ export async function downloadMSTeamsGraphMedia(params: {
         try {
           // SharePoint URLs need to be accessed via Graph shares API
           const shareUrl = att.contentUrl!;
+          if (!isUrlAllowed(shareUrl, allowHosts)) {
+            continue;
+          }
           const encodedUrl = Buffer.from(shareUrl).toString("base64url");
           const sharesUrl = `${GRAPH_ROOT}/shares/u!${encodedUrl}/driveItem/content`;
 
@@ -274,13 +297,20 @@ export async function downloadMSTeamsGraphMedia(params: {
             contentTypeHint: "application/octet-stream",
             preserveFilenames: params.preserveFilenames,
             fetchImpl: async (input, init) => {
+              const requestUrl = resolveRequestUrl(input);
               const headers = new Headers(init?.headers);
               headers.set("Authorization", `Bearer ${accessToken}`);
-              return await fetchFn(resolveRequestUrl(input), {
+              const res = await fetchFn(requestUrl, {
                 ...init,
                 headers,
-                redirect: "follow",
               });
+              const redirectUrl = readRedirectUrl(requestUrl, res);
+              if (redirectUrl && !isUrlAllowed(redirectUrl, allowHosts)) {
+                throw new Error(
+                  `MSTeams media redirect target blocked by allowlist: ${redirectUrl}`,
+                );
+              }
+              return res;
             },
           });
           sharePointMedia.push(media);