CVE-2026-59822
LiteLLM: MCP Authentication Bypass via OAuth2 Passthrough Fallback
Description
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.
INFO
Published Date :
July 8, 2026, 8:16 p.m.
Last Modified :
July 13, 2026, 1:32 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update LiteLLM to version 1.84.0 or later.
- Ensure proper authentication is enforced for all API endpoints.
- Review and validate all authorization headers.
Public PoC/Exploit Available at Github
CVE-2026-59822 has a 2 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-59822.
| URL | Resource |
|---|---|
| https://github.com/BerriAI/litellm/commit/73869f0faf7d11ee21adcb5f91b8c33a340b6c2c | Patch |
| https://github.com/BerriAI/litellm/pull/26463 | Issue Tracking Patch |
| https://github.com/BerriAI/litellm/releases/tag/v1.84.0 | Product Release Notes |
| https://github.com/BerriAI/litellm/security/advisories/GHSA-7488-6r32-c95q | Mitigation Patch Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-59822 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-59822
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
A curated timeline of real AI agent security incidents, breaches, and vulnerabilities (2024-2026). Every entry sourced and dated.
ai-agent-security ai-agents ai-security awesome-list cybersecurity llm-security mcp-security prompt-injection supply-chain-security adversarial-attacks agent-security agentic-ai ai-attacks ai-safety cve incident-response owasp red-team security-research vulnerability
Static scanner for MCP-connected AI agent pipelines — 225 rules across 11 categories, 12 compliance frameworks, OWASP Agentic 10/10 + MCP 10/10, GitHub Action, SARIF, public CVE-to-rule ledger.
ai-agent ai-security claude-code github-action mcp mcp-security owasp sarif scanner security supply-chain-security tool-poisoning ai-agent-security ai-safety security-scanner static-analysis
Python Dockerfile Shell TypeScript HTML Makefile
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-59822 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-59822 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jul. 13, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N Added CPE Configuration OR *cpe:2.3:a:litellm:litellm:*:*:*:*:*:*:*:* versions up to (excluding) 1.84.0 Added Reference Type GitHub, Inc.: https://github.com/BerriAI/litellm/commit/73869f0faf7d11ee21adcb5f91b8c33a340b6c2c Types: Patch Added Reference Type GitHub, Inc.: https://github.com/BerriAI/litellm/pull/26463 Types: Issue Tracking, Patch Added Reference Type GitHub, Inc.: https://github.com/BerriAI/litellm/releases/tag/v1.84.0 Types: Product, Release Notes Added Reference Type GitHub, Inc.: https://github.com/BerriAI/litellm/security/advisories/GHSA-7488-6r32-c95q Types: Mitigation, Patch, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 09, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-59822', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-09T14:31:02.315980Z'} -
New CVE Received by [email protected]
Jul. 08, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'BerriAI', 'product': 'litellm', 'versions': [{'status': 'affected', 'version': '< 1.84.0'}]}] Added Description 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-287 Added CWE CWE-306 Added Reference https://github.com/BerriAI/litellm/commit/73869f0faf7d11ee21adcb5f91b8c33a340b6c2c Added Reference https://github.com/BerriAI/litellm/pull/26463 Added Reference https://github.com/BerriAI/litellm/releases/tag/v1.84.0 Added Reference https://github.com/BerriAI/litellm/security/advisories/GHSA-7488-6r32-c95q