CVE-2026-40217 — litellm
HIGHCVE-2026-40217 is a high-severity (CVSS 8.8) CWE-420 vulnerability in litellm. EPSS puts its 30-day exploitation probability at 17.0% (97th percentile). A fix is available for litellm — see the affected versions and patch details below.
LiteLLM has a sandbox escape in custom-code guardrail
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-40217.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
litellmReal-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
The POST /guardrails/test_custom_code endpoint runs user-supplied Python inside a hand-rolled sandbox. The sandbox can be escaped using bytecode-level techniques, allowing arbitrary code execution in the proxy process — which runs as root in the default Docker image.
Reaching the endpoint requires a proxy-admin credential in default configurations.
Patches
Fixed in 1.83.11. The hand-rolled sandbox has been replaced with RestrictedPython. Upgrade to 1.83.11 or later.
Workarounds
If upgrading is not immediately possible, block POST /guardrails/test_custom_code at your reverse proxy or API gateway.
References
- Patched release:
v1.83.10-stable
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | litellm | ≥ 1.81.8&&< 1.83.10 | 1.83.10pip install --upgrade 'litellm==1.83.10' |
Affected Products
litellmlitellmDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for litellm, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update litellm to 1.83.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-40217 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.
How to detect CVE-2026-40217
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2026-40217 -u https://target- Template
- LiteLLM < 1.25.0 - Remote Code Execution
- Severity
- high
- Impact
- An authenticated attacker with the master key can escape the guardrail sandbox and execute arbitrary commands on the LiteLLM host, potentially as root when using the default container.
- Remediation
- Block /guardrails/test_custom_code at the reverse proxy, restrict admin API access, avoid exposing the management interface to untrusted networks, and do not run LiteLLM as root. Apply vendor patches when available.
Template by ProjectDiscovery nuclei-templates (ritikchaddha), MIT licensed. View the full template. Scan only systems you are authorised to test.
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.
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.Source: Red Hat security advisory for CVE-2026-40217 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Ansible Automation Platform 2.6 | ansible-automation-platform-26/lightspeed-chatbot-rhel9:1780102732 | RHSA-2026:24866 |
| Red Hat OpenShift AI 3.3 | rhoai/odh-llama-stack-core-rhel9:1782310008 | RHSA-2026:30056 |
Frequently Asked Questions
Is CVE-2026-40217 in your dependencies?
Find it across PyPI, including transitive dependencies.