diff --git a/src/infra/net/fetch-guard.ssrf.test.ts b/src/infra/net/fetch-guard.ssrf.test.ts
index a03afba325f..223695c1a53 100644
--- a/src/infra/net/fetch-guard.ssrf.test.ts
+++ b/src/infra/net/fetch-guard.ssrf.test.ts
@@ -18,6 +18,7 @@ describe("fetchWithSsrFGuard hardening", () => {
   it("blocks private and legacy loopback literals before fetch", async () => {
     const blockedUrls = [
       "http://127.0.0.1:8080/internal",
+      "http://[ff02::1]/internal",
       "http://0177.0.0.1:8080/internal",
       "http://0x7f000001/internal",
     ];
diff --git a/src/infra/net/ssrf.test.ts b/src/infra/net/ssrf.test.ts
index e823b35be31..2698bf3db9e 100644
--- a/src/infra/net/ssrf.test.ts
+++ b/src/infra/net/ssrf.test.ts
@@ -1,4 +1,5 @@
 import { describe, expect, it } from "vitest";
+import { blockedIpv6MulticastLiterals } from "../../shared/net/ip-test-fixtures.js";
 import { normalizeFingerprint } from "../tls/fingerprint.js";
 import { isBlockedHostnameOrIp, isPrivateIpAddress } from "./ssrf.js";
 
@@ -38,9 +39,7 @@ const privateIpCases = [
   "fe80::1%lo0",
   "fd00::1",
   "fec0::1",
-  "ff02::1",
-  "ff05::1:3",
-  "[ff02::1]",
+  ...blockedIpv6MulticastLiterals,
   "2001:db8:1234::5efe:127.0.0.1",
   "2001:db8:1234:1:200:5efe:7f00:1",
 ];
diff --git a/src/infra/net/ssrf.ts b/src/infra/net/ssrf.ts
index b84469390c0..8ba29b38e2a 100644
--- a/src/infra/net/ssrf.ts
+++ b/src/infra/net/ssrf.ts
@@ -4,11 +4,11 @@ import { Agent, type Dispatcher } from "undici";
 import {
   extractEmbeddedIpv4FromIpv6,
   isBlockedSpecialUseIpv4Address,
+  isBlockedSpecialUseIpv6Address,
   isCanonicalDottedDecimalIPv4,
   type Ipv4SpecialUseBlockOptions,
   isIpv4Address,
   isLegacyIpv4Literal,
-  isPrivateOrLoopbackIpAddress,
   parseCanonicalIpAddress,
   parseLooseIpAddress,
 } from "../../shared/net/ip.js";
@@ -120,7 +120,7 @@ export function isPrivateIpAddress(address: string, policy?: SsrFPolicy): boolea
     if (isIpv4Address(strictIp)) {
       return isBlockedSpecialUseIpv4Address(strictIp, blockOptions);
     }
-    if (isPrivateOrLoopbackIpAddress(strictIp.toString())) {
+    if (isBlockedSpecialUseIpv6Address(strictIp)) {
       return true;
     }
     const embeddedIpv4 = extractEmbeddedIpv4FromIpv6(strictIp);
diff --git a/src/shared/net/ip-test-fixtures.ts b/src/shared/net/ip-test-fixtures.ts
new file mode 100644
index 00000000000..d2fa9cd5436
--- /dev/null
+++ b/src/shared/net/ip-test-fixtures.ts
@@ -0,0 +1 @@
+export const blockedIpv6MulticastLiterals = ["ff02::1", "ff05::1:3", "[ff02::1]"] as const;
diff --git a/src/shared/net/ip.test.ts b/src/shared/net/ip.test.ts
index a8e4c9bd8e8..f89fb03f7ef 100644
--- a/src/shared/net/ip.test.ts
+++ b/src/shared/net/ip.test.ts
@@ -1,4 +1,5 @@
 import { describe, expect, it } from "vitest";
+import { blockedIpv6MulticastLiterals } from "./ip-test-fixtures.js";
 import {
   extractEmbeddedIpv4FromIpv6,
   isCanonicalDottedDecimalIPv4,
@@ -47,8 +48,9 @@ describe("shared ip helpers", () => {
 
   it("treats blocked IPv6 classes as private/internal", () => {
     expect(isPrivateOrLoopbackIpAddress("fec0::1")).toBe(true);
-    expect(isPrivateOrLoopbackIpAddress("ff02::1")).toBe(true);
-    expect(isPrivateOrLoopbackIpAddress("[ff05::1:3]")).toBe(true);
+    for (const literal of blockedIpv6MulticastLiterals) {
+      expect(isPrivateOrLoopbackIpAddress(literal)).toBe(true);
+    }
     expect(isPrivateOrLoopbackIpAddress("2001:4860:4860::8888")).toBe(false);
   });
 });
diff --git a/src/shared/net/ip.ts b/src/shared/net/ip.ts
index d1f1c0a9069..c386c687898 100644
--- a/src/shared/net/ip.ts
+++ b/src/shared/net/ip.ts
@@ -22,7 +22,7 @@ const PRIVATE_OR_LOOPBACK_IPV4_RANGES = new Set<Ipv4Range>([
   "carrierGradeNat",
 ]);
 
-const PRIVATE_OR_LOOPBACK_IPV6_RANGES = new Set<Ipv6Range>([
+const BLOCKED_IPV6_SPECIAL_USE_RANGES = new Set<Ipv6Range>([
   "unspecified",
   "loopback",
   "linkLocal",
@@ -228,11 +228,15 @@ export function isPrivateOrLoopbackIpAddress(raw: string | undefined): boolean {
   if (isIpv4Address(normalized)) {
     return PRIVATE_OR_LOOPBACK_IPV4_RANGES.has(normalized.range());
   }
-  if (PRIVATE_OR_LOOPBACK_IPV6_RANGES.has(normalized.range())) {
+  return isBlockedSpecialUseIpv6Address(normalized);
+}
+
+export function isBlockedSpecialUseIpv6Address(address: ipaddr.IPv6): boolean {
+  if (BLOCKED_IPV6_SPECIAL_USE_RANGES.has(address.range())) {
     return true;
   }
   // ipaddr.js does not classify deprecated site-local fec0::/10 as private.
-  return (normalized.parts[0] & 0xffc0) === 0xfec0;
+  return (address.parts[0] & 0xffc0) === 0xfec0;
 }
 
 export function isRfc1918Ipv4Address(raw: string | undefined): boolean {