AI Threat Alert
CVE-2026-59822
HIGHLiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. Prior to 1.84.0, LiteLLM's MCP Streamable HTTP endpoint allowed an unauthenticated attacker to use a fabricated Authorization header to trigger an OAuth2 passthrough fallback path that replaced failed LiteLLM key...
Full CISO analysis pending enrichment.
How severe is it?
What should I do?
No patch available
Monitor for updates. Consider compensating controls or temporary mitigations.
Which compliance frameworks are affected?
Compliance analysis pending. Sign in for full compliance mapping when available.
Frequently Asked Questions
What is CVE-2026-59822?
LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. Prior to 1.84.0, LiteLLM's MCP Streamable HTTP endpoint allowed an unauthenticated attacker to use a fabricated Authorization header to trigger an OAuth2 passthrough fallback path that replaced failed LiteLLM key validation with an empty UserAPIKeyAuth() object, allowing requests to reach MCP tooling without a valid LiteLLM key. This issue is fixed in version 1.84.0.
Is CVE-2026-59822 actively exploited?
No confirmed active exploitation of CVE-2026-59822 has been reported, but organizations should still patch proactively.
How to fix CVE-2026-59822?
No patch is currently available. Monitor vendor advisories for updates.
What is the CVSS score for CVE-2026-59822?
No CVSS score has been assigned yet.
What are the technical details?
Original Advisory
LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. Prior to 1.84.0, LiteLLM's MCP Streamable HTTP endpoint allowed an unauthenticated attacker to use a fabricated Authorization header to trigger an OAuth2 passthrough fallback path that replaced failed LiteLLM key validation with an empty UserAPIKeyAuth() object, allowing requests to reach MCP tooling without a valid LiteLLM key. This issue is fixed in version 1.84.0.
Weaknesses (CWE)
CWE-287 Improper Authentication
Primary
CWE-306 Missing Authentication for Critical Function
Primary
CWE-287 Improper Authentication CWE-306 Missing Authentication for Critical Function CWE-287 — Improper Authentication: When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
- [Architecture and Design] Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
Source: MITRE CWE corpus.