Actively exploited in the wild
BerriAI LiteLLM Improper Authentication Vulnerability
BerriAI - LiteLLM · Listed in the CISA KEV since 2026-09-02. This indicates confirmed attacks in production environments.
Required action: 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.
CVE-2026-59822
HighCVSS 8.2KEVExploitation Probability (EPSS)
Elevated risk56th percentile - higher than 56% of all known CVEs
Summary
LiteLLM before version 1.84.0 has a vulnerability in the MCP Streamable HTTP endpoint that allows an unauthenticated attacker to bypass LiteLLM key validation using a crafted Authorization header. The attacker can exploit the OAuth2 passthrough fallback path to replace failed key validation with an empty UserAPIKeyAuth() object, allowing requests to reach MCP tooling without a valid key.
Risk Assessment
The risk is unauthorized access to MCP tooling, potentially leading to data leakage, unauthorized use of AI models, or other resources protected by LiteLLM.
Recommendation
Immediately upgrade LiteLLM to version 1.84.0 or later, which contains the fix for this vulnerability.
Other vulnerabilities in LiteLLM
See all- CVE-2026-37004Critical
BerriAI litellm <=1.82.4 is vulnerable to Server-Side Template Injection (SSTI), allowing unauthenticated remote attackers to execute arbitrary OS commands via a crafted dotprompt_content parameter in the /prompts/test endpoint due to use of an unsandboxed jinja2.Environment.
- CVE-2026-30623Critical
LiteLLM 1.18.10 contains a remote code execution vulnerability in its MCP server creation functionality. The application allows users to add MCP servers via a JSON configuration specifying arbitrary command and args values, which are executed on the host without validation. This enables attackers to run arbitrary operating system commands.
- CVE-2026-49468Critical
LiteLLM proxy before version 1.84.0 has a Host-header parsing flaw that, under specific conditions, allows unauthenticated access to protected management routes. The issue arises from a mismatch between the route evaluated by the auth layer and the route actually dispatched by FastAPI.
- CVE-2026-42271HighActively exploited
LiteLLM versions 1.74.2 through 1.83.6 have a vulnerability in the POST /mcp-rest/test/connection and POST /mcp-rest/test/tools/list endpoints, which accept a full MCP server configuration including commands to execute. An authenticated user with any API key can run arbitrary commands on the proxy host.
- CVE-2026-42208CriticalActively exploited
In LiteLLM versions from 1.81.16 to before 1.83.7, a database query used during proxy API key checks is vulnerable to SQL injection due to mixing caller-supplied key value into the query text. An unauthenticated attacker can send a crafted Authorization header to any LLM API route, leading to reading and potentially modifying data in the proxy's database.
- CVE-2026-40217High
A vulnerability in LiteLLM through 2026-04-08 allows remote attackers to execute arbitrary code via bytecode rewriting at the /guardrails/test_custom_code URI.
- CVE-2026-35030Critical
In LiteLLM prior to 1.83.0, when JWT authentication is enabled (enable_jwt_auth: true), the OIDC userinfo cache uses the first 20 characters of the token as the cache key. JWT tokens produced by the same signing algorithm have identical first 20 characters, allowing an unauthenticated attacker to craft a token matching the cache and inherit a legitimate user's identity and permissions.
- CVE-2026-35029High
LiteLLM before version 1.83.0 has a vulnerability where the /config/update endpoint does not enforce admin role authorization. An authenticated user can modify proxy configuration, environment variables, and register custom pass-through endpoint handlers, leading to remote code execution, arbitrary file reading, and takeover of privileged accounts.
- CVE-2026-108575Medium
A vulnerability has been found in BerriAI LiteLLM up to 1.94.0. This affects the function get_secret of the file secret_managers/main.py of the component Secret Resolution. The manipulation of the argument api_key leads to improper authorization. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
- CVE-2026-108574Medium
A flaw has been found in BerriAI LiteLLM up to 1.95.0. Affected by this issue is the function ui_view_session_spend_logs of the file litellm/proxy/spend_tracking/spend_management_endpoints.py of the component Spend Tracking. Executing a manipulation of the argument session_id can lead to authorization bypass. It is possible to launch the attack remotely. The exploit has been published and may be used. Upgrading to version 1.96.0 can resolve this issue. This patch is called 722d9ffa4f6c5ae15702ab9ab2c5f6bf1688308b. The affected component should be upgraded.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS