CVE-2026-59821: LiteLLM Custom Code Guardrails Bypass Sandboxing

# CVE-2026-59821: LiteLLM Custom Code Guardrails Bypass Sandboxing

https://gcdradar.vercel.app/incidents/cve-2026-59821-litellm-custom-code-guardrails-bypass-sandbox · AIR-2026-0848 · closed 2026-07-08

- Lane: Patch now
- Severity: 2 (Disclosed vulnerability)
- Fix status: Fix status unknown
- First reported: 2026-07-08 (happened 2026-07-22)
- AI role: Attack on AI
- Products: LiteLLM
- CVE ids: CVE-2026-59821
- CVSS: 2.1

## Summary

LiteLLM custom code guardrail creation paths failed to apply proper sandboxing and validation mechanisms. This flaw allowed privileged users to execute arbitrary Python code in the proxy container.

## What to do

No action recorded; read the sources below and the vendor's advisory.

## Latest updates

- 2026-07-22: CVE-2026-59821: LiteLLM: Custom Code Guardrails production endpoints bypass code safety checks (https://github.com/advisories/GHSA-72m8-9m7m-h278)
- 2026-07-08: CVE-2026-59821: LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. (https://nvd.nist.gov/vuln/detail/CVE-2026-59821)

## Sources

- 2026-07-08 NVD: CVE-2026-59821: LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. https://nvd.nist.gov/vuln/detail/CVE-2026-59821
- 2026-07-22 GitHub Advisory Database: CVE-2026-59821: LiteLLM: Custom Code Guardrails production endpoints bypass code safety checks https://github.com/advisories/GHSA-72m8-9m7m-h278

Verify against the vendor's advisory before changing production. Data CC BY-SA 4.0, https://gcdradar.vercel.app.