### CVE-2026-50195 CRI checkpoint import -> local tag poisoning -> code execution ###
EXPECTATION=fixed
containerd: containerd github.com/containerd/containerd/v2 v2.2.5 e53c7c1516c3b2bff98eb76f1f4117477e6f4e66
attacker rootfsImageRef=localhost:5000/attacker:latest
poison target rootfsImageName=localhost:5000/victim:stable
checkpoint config.dump: {"id":"checkpoint-victim","name":"checkpoint-victim","rootfsImage":"localhost:5000/victim:stable","rootfsImageRef":"localhost:5000/attacker:latest","rootfsImageName":"localhost:5000/victim:stable","runtime":"io.containerd.runc.v2","createdTime":"2026-01-01T00:00:00Z","checkpointedTime":"2026-01-01T00:00:00Z"}
PRE: attacker image and victim tag absent from local containerd image store (good)
POD_ID=77b0e1700d6a759049d9fc7efe58a3fd36464f6163804d149f771e5127c5ba33 state=    "state": "SANDBOX_READY"
### Step 1: CRI CreateContainer(image=/checkpoints/malicious.tar) imports malicious checkpoint
checkpoint CreateContainer output: e7657dc92e90aaa08cf150edb8c9f9dc40d9e973f3118f1fdfdbbcb6b3134013
checkpoint container id: e7657dc92e90aaa08cf150edb8c9f9dc40d9e973f3118f1fdfdbbcb6b3134013
POST-CHECKPOINT: attacker image entries = 1
POST-CHECKPOINT: poisoned victim tag entries = 0
localhost:5000/attacker:latest                                          application/vnd.oci.image.manifest.v1+json           sha256:25ff2e0f0b209d91423507e05f4a369614a1014f46b6bceea502fd24fe7d289f 3.5 MiB   linux/amd64 io.cri-containerd.image=managed                                 
### Step 2: normal victim CreateContainer + StartContainer for localhost:5000/victim:stable ###
E0705 07:59:25.223287     340 log.go:32] "CreateContainer in sandbox from runtime service failed" err="rpc error: code = NotFound desc = failed to check if this is a checkpoint image: failed to resolve image \"localhost:5000/victim:stable\": not found" podSandboxID="77b0e1700d6a759049d9fc7efe58a3fd36464f6163804d149f771e5127c5ba33"
time="2026-07-05T07:59:25Z" level=fatal msg="creating container: rpc error: code = NotFound desc = failed to check if this is a checkpoint image: failed to resolve image \"localhost:5000/victim:stable\": not found"
victim CreateContainer failed as expected when the fixed runtime does not create the poisoned local tag
### CRI/containerd summary ###
CONTAINER           IMAGE                          CREATED                  STATE               NAME                  ATTEMPT             POD ID              POD                 NAMESPACE
e7657dc92e90a       localhost:5000/victim:stable   Less than a second ago   Created             checkpoint-importer   1                   77b0e1700d6a7       unknown             unknown
time="2026-07-05T07:59:24.600896406Z" level=info msg="CreateContainer within sandbox \"77b0e1700d6a759049d9fc7efe58a3fd36464f6163804d149f771e5127c5ba33\" for container name:\"checkpoint-importer\" attempt:1"
time="2026-07-05T07:59:24.819850361Z" level=info msg="ImageCreate event name:\"localhost:5000/attacker:latest\""
time="2026-07-05T07:59:25.157678053Z" level=info msg="Prepared e7657dc92e90aaa08cf150edb8c9f9dc40d9e973f3118f1fdfdbbcb6b3134013 for restore"
time="2026-07-05T07:59:25.157724682Z" level=info msg="CreateContainer within sandbox \"77b0e1700d6a759049d9fc7efe58a3fd36464f6163804d149f771e5127c5ba33\" for name:\"checkpoint-importer\" attempt:1 returns container id \"e7657dc92e90aaa08cf150edb8c9f9dc40d9e973f3118f1fdfdbbcb6b3134013\""
time="2026-07-05T07:59:25.222515808Z" level=info msg="CreateContainer within sandbox \"77b0e1700d6a759049d9fc7efe58a3fd36464f6163804d149f771e5127c5ba33\" for container name:\"victim-from-poisoned-tag\" attempt:1"
time="2026-07-05T07:59:25.222916503Z" level=error msg="CreateContainer within sandbox \"77b0e1700d6a759049d9fc7efe58a3fd36464f6163804d149f771e5127c5ba33\" for name:\"victim-from-poisoned-tag\" attempt:1 failed" error="rpc error: code = NotFound desc = failed to check if this is a checkpoint image: failed to resolve image \"localhost:5000/victim:stable\": not found"
VERDICT: FIXED_BLOCKED - fixed containerd did not create the victim tag and no attacker code executed from localhost:5000/victim:stable