{"id":"CVE-2026-44513","aliases":["GHSA-98h9-4798-4q5v","PYSEC-2026-40"],"url":"https://o3.security/vulnerability/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.","published":"2026-05-14T16:26:03.907Z","modified":"2026-08-07T11:31:34.198653758Z","cvss":{"score":8.8,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"diffusers","fixedVersion":"0.38.0"}],"fix":null,"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"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T11:31:34.198653758Z"}}