diff --git a/pyproject.toml b/pyproject.toml
index b8000488..4154662b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -24,7 +24,7 @@ dependencies = [
     "simplejson==4.1.1",
     "packaging==26.3",
     "appdirs==1.4.4",
-    "iphone_backup_decrypt==0.9.0",
+    "iphone_backup_decrypt==0.10.0",
     "pycryptodome>=3.20.0",
     "cryptography==50.0.0",
     "PyYAML>=6.0.2",
diff --git a/src/mvt/android/artifacts/mounts.py b/src/mvt/android/artifacts/mounts.py
index 5a5537b7..0380a785 100644
--- a/src/mvt/android/artifacts/mounts.py
+++ b/src/mvt/android/artifacts/mounts.py
@@ -136,6 +136,10 @@ class Mounts(AndroidArtifact):
             mount_options = fields[5].split(",")
             super_options = fields[separator + 3].split(",")
             options = list(dict.fromkeys(mount_options + super_options))
+            # fields[5] are the per-mount (VFS) flags, the field after the
+            # separator the superblock's; a mount is writable only if both
+            # allow it. The merged list made every read-only overlay a HIGH.
+            is_read_write = "rw" in mount_options and "rw" in super_options
             mount_point = fields[4].replace("\\040", " ")
             device = fields[separator + 2].replace("\\040", " ")
             filesystem_type = fields[separator + 1]
@@ -156,7 +160,7 @@ class Mounts(AndroidArtifact):
                     "options_list": options,
                     "optional_fields": fields[6:separator],
                     "is_system_partition": is_system,
-                    "is_read_write": "rw" in options,
+                    "is_read_write": is_read_write,
                     "process_ids": [process_id],
                 }
             )
@@ -191,7 +195,14 @@ class Mounts(AndroidArtifact):
                     )
 
             # Check for other suspicious mount options
-            suspicious_opts = [opt for opt in options if opt in SUSPICIOUS_OPTIONS]
+            # `rw` sitting in the merged option list is not evidence of
+            # writability (see is_read_write in parse_mountinfo); every other
+            # suspicious option is meaningful in either list.
+            suspicious_opts = [
+                opt
+                for opt in options
+                if opt in SUSPICIOUS_OPTIONS and (opt != "rw" or mount["is_read_write"])
+            ]
             if suspicious_opts and mount["is_system_partition"]:
                 if (
                     "noatime" in mount["mount_options"]
diff --git a/src/mvt/ios/data/ios_versions.json b/src/mvt/ios/data/ios_versions.json
index d8a93c91..8cea66c2 100644
--- a/src/mvt/ios/data/ios_versions.json
+++ b/src/mvt/ios/data/ios_versions.json
@@ -1275,5 +1275,9 @@
     {
         "version": "26.6.2",
         "build": "23G90"
+    },
+    {
+        "version": "27.0",
+        "build": "24A437"
     }
 ]
\ No newline at end of file
diff --git a/src/mvt/ios/decrypt.py b/src/mvt/ios/decrypt.py
index dc30d9c9..ffc7bfa0 100644
--- a/src/mvt/ios/decrypt.py
+++ b/src/mvt/ios/decrypt.py
@@ -52,7 +52,7 @@ class MVTEncryptedBackup(EncryptedBackup):
 
     NOTE: This subclass relies on internal APIs of iphone_backup_decrypt
     (specifically _read_and_unlock_keybag, _keybag, and the Keybag class
-    internals). Pinned to iphone_backup_decrypt==0.9.0.
+    internals). Pinned to iphone_backup_decrypt==0.10.0.
     """
 
     def __init__(self, *, backup_directory, passphrase=None, derived_key=None):
diff --git a/tests/android/test_artifact_mounts.py b/tests/android/test_artifact_mounts.py
new file mode 100644
index 00000000..6b7d1faf
--- /dev/null
+++ b/tests/android/test_artifact_mounts.py
@@ -0,0 +1,43 @@
+# Mobile Verification Toolkit (MVT)
+# Copyright (c) 2021-2026 The MVT Authors.
+# Use of this software is governed by the MVT License 1.1 that can be found at
+#   https://license.mvt.re/1.1/
+"""A mount is writable only if both mountinfo option layers allow it."""
+
+from mvt.android.artifacts.mounts import Mounts
+from mvt.common.alerts import AlertLevel
+
+# fields[5] is the per-mount (VFS) layer, the field after "-" the superblock.
+RO_OVERLAY = (
+    "304 166 0:130 / /product/usr rw,relatime shared:63 - overlay overlay "
+    "ro,seclabel,lowerdir=/mnt/vendor/ext/product/usr:/product/usr"
+)
+RW_SYSTEM = (
+    "305 166 0:131 / /system rw,relatime shared:64 - ext4 /dev/block/dm-1 "
+    "rw,seclabel,errors=panic"
+)
+
+
+def _run(line):
+    mounts = Mounts()
+    mounts.results = Mounts.parse_mountinfo(line, 1)
+    mounts.check_indicators()
+    return mounts
+
+
+class TestMountsReadWriteLayers:
+    def test_rw_vfs_over_ro_superblock_is_not_writable(self):
+        mounts = _run(RO_OVERLAY)
+        assert mounts.results[0]["is_read_write"] is False
+        assert mounts.alertstore.count(AlertLevel.HIGH) == 0
+        assert mounts.alertstore.count(AlertLevel.MEDIUM) == 0
+
+    def test_rw_in_both_layers_still_alerts(self):
+        mounts = _run(RW_SYSTEM)
+        assert mounts.results[0]["is_read_write"] is True
+        assert mounts.alertstore.count(AlertLevel.HIGH) == 1
+
+    def test_both_option_layers_are_still_reported(self):
+        mounts = _run(RO_OVERLAY)
+        options = mounts.results[0]["options_list"]
+        assert "rw" in options and "ro" in options
diff --git a/uv.lock b/uv.lock
index a1cc5fa4..085b1a35 100644
--- a/uv.lock
+++ b/uv.lock
@@ -609,14 +609,14 @@ wheels = [
 
 [[package]]
 name = "iphone-backup-decrypt"
-version = "0.9.0"
+version = "0.10.0"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
     { name = "pycryptodome" },
 ]
-sdist = { url = "https://files.pythonhosted.org/packages/6f/e7/bcdacdec21d628122ba240e7f742ab2175149e58672be63af55ff37a0f28/iphone_backup_decrypt-0.9.0.tar.gz", hash = "sha256:13b18fef3c8e3af627914f8c1a429bbc5555dfb0505239ba49efe99984cc0c96", size = 16125, upload-time = "2024-09-18T15:50:12.179Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/01/b8/a2ec2b10d792403d36bb6661fea6357179c31ece1ed3285c442e636d6335/iphone_backup_decrypt-0.10.0.tar.gz", hash = "sha256:5f2799e58f908cce28d7929dd82231abc8acd57c25b37bce6a2d6a82e018d343", size = 20000, upload-time = "2026-09-17T21:46:44Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/b8/94/64a31be93f72e0a254bde68e4cf7d24aef37a0a985754a197fa1b028a665/iphone_backup_decrypt-0.9.0-py3-none-any.whl", hash = "sha256:55b5adfafac757f58aa6444b83a4cc2c20cdd699c6ff1d2f4b549936a5dad92c", size = 15767, upload-time = "2024-09-18T15:50:10.537Z" },
+    { url = "https://files.pythonhosted.org/packages/89/10/349b2a720e012921d1457e1d1c2b921b16300a5f3570c4c64d0d3787539f/iphone_backup_decrypt-0.10.0-py3-none-any.whl", hash = "sha256:1ac4345a07b104a3eacab20932b8621cd1e0164e0f03d913e66eed6ea5ee173e", size = 17400, upload-time = "2026-09-17T21:46:42Z" },
 ]
 
 [[package]]
@@ -1038,7 +1038,7 @@ requires-dist = [
     { name = "betterproto2", specifier = "==0.10.0" },
     { name = "click", specifier = "==8.4.2" },
     { name = "cryptography", specifier = "==50.0.0" },
-    { name = "iphone-backup-decrypt", specifier = "==0.9.0" },
+    { name = "iphone-backup-decrypt", specifier = "==0.10.0" },
     { name = "nskeyedunarchiver", specifier = "==1.5.2" },
     { name = "packaging", specifier = "==26.3" },
     { name = "pyahocorasick", specifier = "==2.3.1" },