diff --git a/ps2xRuntime/src/lib/Kernel/Syscalls/Helpers/Runtime.h b/ps2xRuntime/src/lib/Kernel/Syscalls/Helpers/Runtime.h
index 690936401..501d72586 100644
--- a/ps2xRuntime/src/lib/Kernel/Syscalls/Helpers/Runtime.h
+++ b/ps2xRuntime/src/lib/Kernel/Syscalls/Helpers/Runtime.h
@@ -118,12 +118,65 @@ inline std::string translatePs2Path(const char *ps2Path)
     auto resolveWithBase = [&](const std::filesystem::path &base, const std::string &suffix) -> std::string
     {
         const std::string normalizedSuffix = normalizePs2PathSuffix(suffix);
-        std::filesystem::path resolved = base;
+        const std::filesystem::path normalizedBase = base.lexically_normal();
+        std::filesystem::path resolved = normalizedBase;
         if (!normalizedSuffix.empty())
         {
             resolved /= std::filesystem::path(normalizedSuffix);
         }
-        return resolved.lexically_normal().string();
+
+        const std::filesystem::path normalizedPath = resolved.lexically_normal();
+        std::error_code ec;
+        const std::filesystem::path canonicalBase = std::filesystem::weakly_canonical(normalizedBase, ec);
+        if (ec)
+        {
+            return {};
+        }
+        const std::filesystem::path canonicalPath = std::filesystem::weakly_canonical(normalizedPath, ec);
+        if (ec)
+        {
+            return {};
+        }
+
+        std::size_t baseDepth = 0;
+        for (auto it = canonicalBase.begin(); it != canonicalBase.end(); ++it)
+        {
+            ++baseDepth;
+        }
+        std::size_t pathDepth = 0;
+        for (auto it = canonicalPath.begin(); it != canonicalPath.end(); ++it)
+        {
+            ++pathDepth;
+        }
+        if (pathDepth < baseDepth)
+        {
+            return {};
+        }
+
+        std::filesystem::path candidateBase = canonicalPath;
+        while (pathDepth-- > baseDepth)
+        {
+            candidateBase = candidateBase.parent_path();
+        }
+
+        const bool baseExists = std::filesystem::exists(canonicalBase, ec);
+        if (ec)
+        {
+            return {};
+        }
+        if (baseExists)
+        {
+            const bool sameBase = std::filesystem::equivalent(canonicalBase, candidateBase, ec);
+            if (ec || !sameBase)
+            {
+                return {};
+            }
+        }
+        else if (canonicalBase != candidateBase)
+        {
+            return {};
+        }
+        return normalizedPath.string();
     };
 
     if (lower.rfind("host0:", 0) == 0 || lower.rfind("host:", 0) == 0)
@@ -151,7 +204,11 @@ inline std::string translatePs2Path(const char *ps2Path)
 
     if (pathStr.size() > 1 && pathStr[1] == ':')
     {
+#ifdef _WIN32
+        return resolveWithBase(getConfiguredCdRoot(), pathStr);
+#else
         return pathStr;
+#endif
     }
 
     return resolveWithBase(getConfiguredCdRoot(), pathStr);
diff --git a/ps2xTest/src/ps2_runtime_io_tests.cpp b/ps2xTest/src/ps2_runtime_io_tests.cpp
index 1e920515b..8fd000060 100644
--- a/ps2xTest/src/ps2_runtime_io_tests.cpp
+++ b/ps2xTest/src/ps2_runtime_io_tests.cpp
@@ -344,6 +344,91 @@ void register_ps2_runtime_io_tests()
                 "mc0: directory should NOT exist under cdRoot");
         });
 
+        tc.Run("PS2 paths cannot escape configured roots", [](TestCase &t)
+        {
+            TestContext test;
+
+            t.Equals(translatePs2Path("mc0:../outside.dat"), std::string(),
+                     "mc0: traversal should be rejected");
+            t.Equals(translatePs2Path("cdrom:../../outside.dat"), std::string(),
+                     "cdrom: traversal should be rejected");
+            t.Equals(translatePs2Path("host:..\\..\\outside.dat"), std::string(),
+                     "mixed slash traversal should be rejected");
+
+            std::error_code ec;
+            std::filesystem::create_directory_symlink(test.paths.base,
+                                                      test.paths.mcRoot / "escape", ec);
+#ifndef _WIN32
+            t.IsFalse(static_cast<bool>(ec), "symlink traversal fixture should be created");
+#endif
+            if (!ec)
+            {
+                t.Equals(translatePs2Path("mc0:/escape/outside.dat"), std::string(),
+                         "symlink traversal should be rejected");
+            }
+        });
+
+        tc.Run("PS2 path normalization preserves valid paths", [](TestCase &t)
+        {
+            TestContext test;
+
+            t.Equals(translatePs2Path("mc0:/dir/../save.dat"),
+                     (test.paths.mcRoot / "save.dat").string(),
+                     "valid traversal within mcRoot should be preserved");
+            t.Equals(translatePs2Path("host:/config.ini"),
+                     (test.paths.cdRoot / "config.ini").string(),
+                     "host: path should resolve under hostRoot");
+            t.Equals(translatePs2Path("cdrom:/DATA.BIN;1"),
+                     (test.paths.cdRoot / "DATA.BIN").string(),
+                     "cdrom: path should preserve ISO version handling");
+            t.Equals(translatePs2Path("mc0:/SAVEDATA/save.dat"),
+                     (test.paths.mcRoot / "SAVEDATA" / "save.dat").string(),
+                     "mc0: path should resolve under mcRoot");
+#ifdef _WIN32
+            const std::filesystem::path directPath = test.paths.cdRoot / "inside.dat";
+            t.Equals(translatePs2Path(directPath.string().c_str()), directPath.string(),
+                     "direct Windows paths inside cdRoot should be preserved");
+            std::string caseVariant = directPath.string();
+            if (!caseVariant.empty() && caseVariant.front() >= 'A' && caseVariant.front() <= 'Z')
+            {
+                caseVariant.front() = static_cast<char>(caseVariant.front() - 'A' + 'a');
+            }
+            else if (!caseVariant.empty() && caseVariant.front() >= 'a' && caseVariant.front() <= 'z')
+            {
+                caseVariant.front() = static_cast<char>(caseVariant.front() - 'a' + 'A');
+            }
+            t.IsFalse(translatePs2Path(caseVariant.c_str()).empty(),
+                      "Windows containment should compare path components case-insensitively");
+            t.Equals(translatePs2Path("C:\\outside.dat"), std::string(),
+                     "direct Windows paths outside cdRoot should be rejected");
+#else
+            t.Equals(translatePs2Path("C:\\outside.dat"), std::string("C:\\outside.dat"),
+                     "drive-shaped paths should preserve non-Windows behavior");
+#endif
+        });
+
+        tc.Run("fioOpen rejects paths outside configured roots", [](TestCase &t)
+        {
+            TestContext test;
+            const uint32_t pathAddr = GUEST_STRING_AREA_START + 0x300;
+            const std::filesystem::path escapedPath = test.paths.base / "outside.dat";
+            writeGuestString(test.rdram.data(), pathAddr, "mc0:../outside.dat");
+
+            setRegU32(test.ctx, 4, pathAddr);
+            setRegU32(test.ctx, 5, PS2_FIO_WRITE_CREATE_TRUNC);
+            fioOpen(test.rdram.data(), &test.ctx, nullptr);
+
+            const int32_t fd = getRegS32(&test.ctx, 2);
+            if (fd >= 0)
+            {
+                setRegU32(test.ctx, 4, static_cast<uint32_t>(fd));
+                fioClose(test.rdram.data(), &test.ctx, nullptr);
+            }
+            t.Equals(fd, -1, "fioOpen should reject traversal outside mcRoot");
+            t.IsFalse(std::filesystem::exists(escapedPath),
+                      "fioOpen should not create a file outside mcRoot");
+        });
+
         tc.Run("sceMc open write read and close roundtrip through sync", [](TestCase &t)
         {
             TestContext test;