diff --git a/frigate/test/test_camera_maintainer.py b/frigate/test/test_camera_maintainer.py
new file mode 100644
index 0000000000..c03d965784
--- /dev/null
+++ b/frigate/test/test_camera_maintainer.py
@@ -0,0 +1,79 @@
+"""Tests for CameraMaintainer SHM cleanup on camera remove.
+
+Regression coverage for the case where a camera is removed and then a
+new camera is added with the same name. Without unlinking the per-frame
+YUV SHM slots, the maintainer's frame_manager.create call hits
+FileExistsError and falls back to reopening the existing segment at the
+*old* size, which the new ffmpeg process then writes mismatched-size
+frames into.
+"""
+
+import unittest
+from unittest.mock import MagicMock, patch
+
+from frigate.camera.maintainer import CameraMaintainer
+
+
+class TestMaintainerUnlinkFrameSlotsOnRemove(unittest.TestCase):
+    def _make_maintainer(self) -> CameraMaintainer:
+        """Build a maintainer without invoking __init__ (avoids needing real
+        FrigateConfig, queues, multiprocessing manager, etc.). We're only
+        exercising the SHM-cleanup helper, so the surrounding init is
+        irrelevant."""
+        maintainer = CameraMaintainer.__new__(CameraMaintainer)
+        maintainer.frame_manager = MagicMock()
+        return maintainer
+
+    def test_unlinks_only_segments_with_matching_prefix(self) -> None:
+        maintainer = self._make_maintainer()
+        maintainer.frame_manager.shm_store = {
+            "front_frame0": object(),
+            "front_frame1": object(),
+            "front_frame2": object(),
+            # Different camera; must not be touched.
+            "side_frame0": object(),
+            # Detector input/output buffers are sized by the model and
+            # cached by the long-lived DetectorRunner — must not be
+            # touched even when their owning camera is removed.
+            "front": object(),
+            "out-front": object(),
+        }
+
+        # __name-mangled access from outside the class.
+        maintainer._CameraMaintainer__unlink_camera_frame_slots("front")
+
+        deleted = [c.args[0] for c in maintainer.frame_manager.delete.call_args_list]
+        self.assertEqual(
+            sorted(deleted),
+            ["front_frame0", "front_frame1", "front_frame2"],
+        )
+
+    def test_handles_camera_with_no_slots(self) -> None:
+        """Cameras that were removed before any frame slot was ever
+        created (e.g. cancelled during preparing_clip) should be a no-op."""
+        maintainer = self._make_maintainer()
+        maintainer.frame_manager.shm_store = {"other_frame0": object()}
+
+        maintainer._CameraMaintainer__unlink_camera_frame_slots("front")
+
+        maintainer.frame_manager.delete.assert_not_called()
+
+    def test_swallows_delete_errors(self) -> None:
+        """Unlink failures shouldn't abort the remove loop — best-effort."""
+        maintainer = self._make_maintainer()
+        maintainer.frame_manager.shm_store = {
+            "front_frame0": object(),
+            "front_frame1": object(),
+        }
+        maintainer.frame_manager.delete.side_effect = OSError("simulated")
+
+        # Both slots are attempted; the OSError on the first doesn't
+        # prevent the second from being tried.
+        with patch("frigate.camera.maintainer.logger"):
+            maintainer._CameraMaintainer__unlink_camera_frame_slots("front")
+
+        self.assertEqual(maintainer.frame_manager.delete.call_count, 2)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/frigate/test/test_shared_memory_frame_manager.py b/frigate/test/test_shared_memory_frame_manager.py
new file mode 100644
index 0000000000..352a0bc619
--- /dev/null
+++ b/frigate/test/test_shared_memory_frame_manager.py
@@ -0,0 +1,137 @@
+"""Tests for SharedMemoryFrameManager cache invalidation.
+
+Covers the case where a SHM segment is unlinked and recreated at a
+different size across a camera add/remove cycle while a long-lived
+in-process cache (e.g. TrackedObjectProcessor) still holds a ref to
+the old, smaller segment.
+"""
+
+import unittest
+from types import SimpleNamespace
+from unittest.mock import patch
+
+import numpy as np
+
+from frigate.util.image import SharedMemoryFrameManager
+
+
+def _fake_shm(size: int) -> SimpleNamespace:
+    """A minimal stand-in for UntrackedSharedMemory with .size and .buf."""
+    return SimpleNamespace(size=size, buf=bytearray(size), close=lambda: None)
+
+
+class TestSharedMemoryFrameManagerGet(unittest.TestCase):
+    def test_get_reopens_when_cached_segment_is_smaller_than_shape(self) -> None:
+        """A cached ref to an older smaller segment must be dropped and the
+        current (larger) segment reopened. Without this, np.ndarray would
+        raise "buffer is too small for requested array" when the in-memory
+        cache pointed at an old SHM after a same-name resize."""
+        manager = SharedMemoryFrameManager()
+
+        small = _fake_shm(size=100)
+        large = _fake_shm(size=10_000)
+        manager.shm_store["cam_frame0"] = small
+
+        with patch("frigate.util.image.UntrackedSharedMemory", return_value=large):
+            arr = manager.get("cam_frame0", (50, 50))
+
+        self.assertIsNotNone(arr)
+        # Numpy now reports against the large segment, not the small one.
+        self.assertEqual(arr.shape, (50, 50))
+        self.assertIs(manager.shm_store["cam_frame0"], large)
+
+    def test_get_keeps_cached_segment_when_size_sufficient(self) -> None:
+        """Don't pay the reopen cost when the cached ref is fine."""
+        manager = SharedMemoryFrameManager()
+
+        cached = _fake_shm(size=10_000)
+        manager.shm_store["cam_frame0"] = cached
+
+        with patch("frigate.util.image.UntrackedSharedMemory") as untracked_shm_cls:
+            arr = manager.get("cam_frame0", (50, 50))
+            untracked_shm_cls.assert_not_called()
+
+        self.assertIsNotNone(arr)
+        self.assertIs(manager.shm_store["cam_frame0"], cached)
+
+    def test_get_opens_fresh_when_no_cache_entry(self) -> None:
+        manager = SharedMemoryFrameManager()
+        fresh = _fake_shm(size=10_000)
+
+        with patch("frigate.util.image.UntrackedSharedMemory", return_value=fresh):
+            arr = manager.get("cam_frame0", (50, 50))
+
+        self.assertIsNotNone(arr)
+        self.assertIs(manager.shm_store["cam_frame0"], fresh)
+
+    def test_get_returns_none_when_segment_missing(self) -> None:
+        manager = SharedMemoryFrameManager()
+
+        with patch(
+            "frigate.util.image.UntrackedSharedMemory",
+            side_effect=FileNotFoundError,
+        ):
+            arr = manager.get("cam_frame0", (50, 50))
+
+        self.assertIsNone(arr)
+
+    def test_get_returns_none_when_reopened_segment_is_still_too_small(self) -> None:
+        """Race during a same-name SHM recreate: cache is stale, we reopen
+        by name, but the maintainer hasn't allocated the new segment yet —
+        the reopened ref is also too small. Skip the frame (return None)
+        rather than crash on np.ndarray."""
+        manager = SharedMemoryFrameManager()
+
+        small_cached = _fake_shm(size=100)
+        still_small_after_reopen = _fake_shm(size=100)
+        manager.shm_store["cam_frame0"] = small_cached
+
+        with patch(
+            "frigate.util.image.UntrackedSharedMemory",
+            return_value=still_small_after_reopen,
+        ):
+            arr = manager.get("cam_frame0", (50, 50))
+
+        self.assertIsNone(arr)
+        # Don't cache the too-small reopened ref — next call will re-open
+        # once the maintainer has finished recreating the segment.
+        self.assertNotIn("cam_frame0", manager.shm_store)
+
+    def test_get_handles_n_dimensional_shape(self) -> None:
+        """np.prod must be used (not raw multiplication) for tuple shapes."""
+        manager = SharedMemoryFrameManager()
+        # YUV-shaped frame: (height * 3/2, width) for 1920x1080 = 3,110,400
+        big_enough = _fake_shm(size=3_110_400)
+        manager.shm_store["cam_frame0"] = big_enough
+
+        with patch("frigate.util.image.UntrackedSharedMemory") as untracked_shm_cls:
+            arr = manager.get("cam_frame0", (1620, 1920))
+            untracked_shm_cls.assert_not_called()
+
+        self.assertIsNotNone(arr)
+        self.assertEqual(arr.shape, (1620, 1920))
+
+
+class TestSharedMemoryFrameManagerGetRecreatesLargerSegment(unittest.TestCase):
+    """End-to-end-style: simulates the full unlink-and-recreate cycle."""
+
+    def test_segment_grows_then_get_succeeds(self) -> None:
+        manager = SharedMemoryFrameManager()
+
+        # Phase 1: existing camera at 320x240 YUV — 320 * 240 * 1.5 = 115_200
+        small = _fake_shm(size=115_200)
+        manager.shm_store["cam_frame0"] = small
+        arr_small = np.ndarray((360, 320), dtype=np.uint8, buffer=small.buf)
+        self.assertEqual(arr_small.shape, (360, 320))
+
+        # Phase 2: restart at 1920x1080 — new SHM segment, larger size.
+        large = _fake_shm(size=3_110_400)
+        with patch("frigate.util.image.UntrackedSharedMemory", return_value=large):
+            arr_large = manager.get("cam_frame0", (1620, 1920))
+
+        self.assertIsNotNone(arr_large)
+        self.assertEqual(arr_large.shape, (1620, 1920))
+
+
+if __name__ == "__main__":
+    unittest.main()