High 8.8Known exploited (CISA KEV)Published Jul 8, 2026

CVE-2026-59822LiteLLM: MCP Authentication Bypass via OAuth2 Passthrough Fallback

Updated under an hour ago (2026-10-19 09:00 UTC)

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It affects BerriAI litellm and 1 other product. Add what you run to find out whether that includes you.

CISA lists it as known exploited since Sep 2, 2026; federal agencies had to remediate by Sep 16, 2026. Treat that date as your deadline.

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Every CVE for BerriAI litellm

Exploited in the last 30 days

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: 8.8 HIGH (v4.0, CNA)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
Weakness (CWE): CWE-287, CWE-306
Known exploited: Added to CISA KEV Sep 2, 2026; federal remediation due Sep 16, 2026Apply 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.
EPSS (exploitation in the next 30 days): 0.84% (percentile 57)
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Sep 3, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

BerriAI litellm berriai:litellm (from the name)	before 1.84.0	CNA record
litellm litellm litellm:litellm	before 1.84.0	NVD

References

https://github.com/BerriAI/litellm/security/advisories/GHSA-7488-6r32-c95qx-refsource-confirm, mitigation, patch, vendor-advisory
https://github.com/BerriAI/litellm/pull/26463x-refsource-misc, issue-tracking, patch
https://github.com/BerriAI/litellm/commit/73869f0faf7d11ee21adcb5f91b8c33a340b6c2cx-refsource-misc, patch
https://github.com/BerriAI/litellm/releases/tag/v1.84.0x-refsource-misc, product, release-notes
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-59822us-government-resource
https://www.wiz.io/blog/ai-infrastructure-honeypotthird-party-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.