CVE-2026-31235 — Pickle deserialization in imgaug BackgroundAugmenter worker queue

MITRE service request: 1988584

Status: RESERVED (pending a qualifying public reference per CNA Rules §5.3).

Official CVE description

The imgaug library thru 0.4.0 contains an insecure deserialization vulnerability in its BackgroundAugmenter class within the multicore.py module. The class uses Python’s pickle module to deserialize data received via a multiprocessing queue in the _augment_images_worker() method without any safety checks. An attacker who can influence the data placed into this queue (e.g., through social engineering, malicious input scripts, or a compromised shared queue) can provide a malicious pickle payload. When deserialized, this payload can execute arbitrary code in the context of the worker process, leading to remote or local code execution depending on the deployment scenario.

Summary

Worker processes call pickle.loads(batch_str) on queue-fed blobs. Any participant who can poison the multiprocessing queue (shared notebook, malicious “optimization” snippet, or compromised parent) gains code execution inside augmentation workers.

Affected product and versions

Technical details

Risk

High in collaborative ML preprocessing environments.

Remediation / workaround

CVE Program next steps