CVE-2026-59822
high CISA KEVBerriAI LiteLLM Improper Authentication Vulnerability
Vendor / product: BerriAI — LiteLLM
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N Required action (CISA)
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Affected products
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
References
- https://github.com/BerriAI/litellm/commit/73869f0faf7d11ee21adcb5f91b8c33a340b6c2c security-advisories@github.com
- https://github.com/BerriAI/litellm/pull/26463 security-advisories@github.com
- https://github.com/BerriAI/litellm/releases/tag/v1.84.0 security-advisories@github.com
- https://github.com/BerriAI/litellm/security/advisories/GHSA-7488-6r32-c95q security-advisories@github.com
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-59822 134c704f-9b21-4f2e-91b3-4a467353bcc0
- https://www.wiz.io/blog/ai-infrastructure-honeypot 134c704f-9b21-4f2e-91b3-4a467353bcc0