Your RSA-2048 keys break in 2030. Find every one of them before attackers do.
🐍
🐍 PyPI
Not in CISA KEV
HIGH severity

GHSA-98h9-4798-4q5v

HIGHFix: huggingface/diffusers#13448

GHSA-98h9-4798-4q5v is a high-severity (CVSS 8.8) remote code execution vulnerability in diffusers. O3 Security confirms whether GHSA-98h9-4798-4q5v is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Diffusers has a `trust_remote_code` bypass via `custom_pipeline` and local custom components

Also known asCVE-2026-44513PYSEC-2026-40
Published
May 7, 2026
Updated
Jun 5, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Jun 5, 2026 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected
🐍diffusers

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Impact

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.

Patches

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.

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

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐍PyPIdiffusersall versions0.38.0

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for diffusers. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update diffusers to 0.38.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-98h9-4798-4q5v is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether GHSA-98h9-4798-4q5v is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-98h9-4798-4q5v. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Impact 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', cust
O3 Security · Impact-Aware SCA

Is GHSA-98h9-4798-4q5v in your dependencies?

O3 detects GHSA-98h9-4798-4q5v across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works
GHSA-98h9-4798-4q5v: diffusers Remote… | O3 Security