CVE-2026-59822

CVE Enrichment

CVSS: 8.8 HIGH
EPSS: 0.84%
EPSS Percentile: 56.55%
CISA KEV: YES — Known Exploited Vulnerability

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.

Technical Details

CVSS Version: 4.0
CNA / NVD Source: security-advisories@github.com
Published: 09-Jul-2026 03:16
Last Modified: 03-Sep-2026 20:05
EPSS Date: 2026-10-12
CWE: CWE-287, CWE-306

CVSS Vector


            CVSS:4.0                            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

CISA KEV Details

Date Added: 2026-09-02
Remediation Due: 2026-09-16
Known Ransomware Campaign Use: Unknown
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.
Notes: https://github.com/BerriAI/litellm/security/advisories/GHSA-7488-6r32-c95q ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-59822

Affected Products / Versions

litellm / litellm
Version / affected range: * · before (exclusive) 1.84.0
cpe:2.3:a:litellm:litellm:*:*:*:*:*:*:*:*

References

Last enrichment sync: 12-Oct-2026 23:30
Sources: NVD · FIRST EPSS · CISA KEV
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Reported Context (2)

MCP authentication bypass via the MCP endpoint (CVE-2026-59822) - an arbitrary Bearer token can create a valid session; confirmed as exploitable across hundreds of Internet-facing instances. Researchers Detail LiteLLM Authentication Bypass, Root-Level RCE and Cloud Credential Theft
Earlier this year, Wiz Research discovered an authentication flaw in LiteLLM's MCP Gateway (CVE-2026-59822). The vulnerability sits in the OAuth2 header handling: when token validation fails, rather than rejecting the Wiz Details 90 Days of Attacks on AI Infrastructure

CVE (4)

Malware (1)

Threat Actors (1)

MITRE ATT&CK (8)

Vendors (2)

Products (19)

Tools (1)

Industries (2)

Note: Related entities, including threat actors, malware, CVEs, MITRE ATT&CK techniques, vendors, products, tools, countries, and industries, are shown when they appear in the same reporting. Their presence does not necessarily mean they were targeted, compromised, vulnerable, responsible for the activity, or directly involved in the incident.