CVE-2026-44513

Workarounds

If upgrading immediately is not possible:

• Only call from_pretrained with pretrained_model_name_or_path, custom_pipeline, and local snapshot directories from fully trusted sources that have been audited.
• Do not pass custom_pipeline= pointing at a Hub repository different from the primary pretrained_model_name_or_path before reading its pipeline.py.
• Before calling from_pretrained on a local snapshot, inspect the snapshot for unexpected *.py files, especially under component subdirectories (unet/, scheduler/, etc.) and at the snapshot root.

These are mitigations, not fixes, the only complete remediation is upgrading to 0.38.0.

Resources

• Fix: https://github.com/huggingface/diffusers/pull/13448
• Original issue: https://github.com/huggingface/diffusers/issues/13446
• Release notes: https://github.com/huggingface/diffusers/releases/tag/v0.38.0
• CWE-94: https://cwe.mitre.org/data/definitions/94.html

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:

1. Cross-repo custom_pipeline. 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.
2. Local snapshot + Hub custom_pipeline. 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.
3. Local snapshot with custom components. 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.

Silent remote code execution on the victim's machine. Anyone calling DiffusionPipeline.from_pretrained with custom pipelines is impacted.

Untrusted input is evaluated as executable code within the application's runtime environment. Typical impact: arbitrary code execution within the application's privilege context.

CVE-2026-44513 has a CVSS score of 8.8 (High). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.38.0); upgrading removes the vulnerable code path.

Kodem intelligence

Yes. Fixed in diffusers 0.38.0 via PR #13448. All users on versions < 0.38.0 should upgrade:

pip install --upgrade "diffusers>=0.38.0"

The fix moves the trust_remote_code gate out of DiffusionPipeline.download() and into get_cached_module_file in src/diffusers/utils/dynamic_modules_utils.py, which is the actual chokepoint for every dynamic module load (local, Hub, or community mirror). All three variants now raise ValueError instead of executing untrusted code.

1. What is CVE-2026-44513? CVE-2026-44513 is a high-severity code injection vulnerability in diffusers (pip), affecting versions < 0.38.0. It is fixed in 0.38.0. Untrusted input is evaluated as executable code within the application's runtime environment.
2. How severe is CVE-2026-44513? CVE-2026-44513 has a CVSS score of 8.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of diffusers are affected by CVE-2026-44513? diffusers (pip) versions < 0.38.0 is affected.
4. Is there a fix for CVE-2026-44513? Yes. CVE-2026-44513 is fixed in 0.38.0. Upgrade to this version or later.
5. Is CVE-2026-44513 exploitable, and should I be worried? Whether CVE-2026-44513 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-44513 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-44513? Upgrade diffusers to 0.38.0 or later.