{"id":"CVE-2026-44513","summary":"Diffusers: `trust_remote_code` bypass via `custom_pipeline` and local custom components","details":"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.","aliases":["GHSA-98h9-4798-4q5v","PYSEC-2026-40"],"modified":"2026-07-09T03:51:21.610296752Z","published":"2026-05-14T16:26:03.907Z","related":["CGA-69gx-4592-cv3j"],"database_specific":{"cna_assigner":"GitHub_M","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44513.json","cwe_ids":["CWE-94"]},"references":[{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44513.json"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2026-44513"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44513.json"},{"type":"ADVISORY","url":"https://github.com/huggingface/diffusers/security/advisories/GHSA-98h9-4798-4q5v"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-44513"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2477507"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/huggingface/diffusers","events":[{"introduced":"0"},{"fixed":"275869dcae4ebcfee6a80253fdabc56033335020"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"0.38.0"}],"source":["AFFECTED_FIELD","CPE_RANGE"],"cpe":"cpe:2.3:a:huggingface:diffusers:*:*:*:*:*:python:*:*"}}],"versions":["v0.16.0","v0.15.0","v0.14.0","v0.13.0","v0.12.0","v0.11.0","v0.10.0","v0.9.0","v0.8.0","v0.7.0","v0.6.0","v0.5.0","v0.4.1","v0.4.0","v0.3.0","v0.2.4","v0.2.3","v0.2.2","v0.2.1","v0.2.0","0.1.3","0.1.2","0.1.1","0.1.0","v0.0.4","v0.0.3"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-44513.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"}]}