GHSA-98h9-4798-4q5v is a high-severity (CVSS 8.8) Code Injection vulnerability in diffusers. A fix is available for diffusers — see the affected versions and patch details below.
Diffusers has a `trust_remote_code` bypass via `custom_pipeline` and local custom components
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-98h9-4798-4q5v.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-98h9-4798-4q5v plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
diffusersReal-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:
- Cross-repo
custom_pipeline.DiffusionPipeline.from_pretrained('repoA', custom_pipeline='attacker/repoB', trust_remote_code=False)— the gate evaluated againstrepoA's file list rather thanrepoB's, sorepoB'spipeline.pywas loaded and executed. - Local snapshot + Hub
custom_pipeline.DiffusionPipeline.from_pretrained('/local/snapshot', custom_pipeline='attacker/repoB', trust_remote_code=False)— the local-path branch never invokeddownload(), so the gate was never reached and remote code fromrepoBexecuted. - 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 frommodel_index.json— same root cause; the local path skippeddownload()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_pretrainedwithpretrained_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 primarypretrained_model_name_or_pathbefore reading itspipeline.py. - Before calling
from_pretrainedon a local snapshot, inspect the snapshot for unexpected*.pyfiles, 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
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | diffusers | all versions | 0.38.0pip install --upgrade 'diffusers==0.38.0' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for diffusers, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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.
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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-98h9-4798-4q5v can be triaged on real exposure rather than presence alone.
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.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This is an Important vulnerability in Diffusers, a library used in Red Hat AI/ML offerings, that allows arbitrary remote code execution. The `trust_remote_code` security mechanism in `DiffusionPipeline.from_pretrained` can be bypassed, enabling the loading and execution of malicious code despite explicit security…
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat AI Inference Server 3.4 | rhaii/vllm-cpu-rhel9:1789681128 | RHSA-2026:69466 |
| Red Hat AI Inference Server 3.4 | rhaii/vllm-cuda-rhel9:1789681126 | RHSA-2026:69467 |
| Red Hat AI Inference Server 3.4 | rhaii/vllm-cpu-rhel9:1790075793 | RHSA-2026:70965 |
| Red Hat AI Inference Server 3.4 | rhaii/vllm-cuda-rhel9:1790090131 | RHSA-2026:70979 |
| Red Hat OpenShift AI 3.4 | rhoai/odh-th06-cuda130-torch210-py312-rhel9:1787077779 | RHSA-2026:60520 |
Frequently Asked Questions
Is GHSA-98h9-4798-4q5v in your dependencies?
O3 Security finds GHSA-98h9-4798-4q5v across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.