Vulnerability · Published May 14, 2026 · Assigned by GitHub_M
CVE-2026-44513Diffusers: `trust_remote_code` bypass via `custom_pipeline` and local custom components
High 8.8
In plain English
A high-severity code injection in diffusers from huggingface. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.1% (higher than 65% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | diffusers | 0.38.0 | GHSA-98h9-4798-4q5v |
| PyPI | diffusers | 0.38.0 | PYSEC-2026-40 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| huggingface | diffusers | < 0.38.0 |
Weakness: CWE-94, CWE-358 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
References
- https://github.com/huggingface/diffusers/security/advisories/GHSA-98h9-4798-4q5v x_refsource_CONFIRM
- https://access.redhat.com/security/cve/CVE-2026-44513 vdb-entry, x_refsource_REDHAT
- RHBZ#2477507 issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44513.json x_sadp-csaf-vex
- https://access.redhat.com/errata/RHSA-2026:60520 vendor-advisory, x_refsource_REDHAT