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Vulnerability Intelligence

CVE-2026-59822

HighExploitedPublic exploit

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…

Published Jul 8, 2026 · Updated Sep 10, 2026 · Also known as EUVD-2026-42359, GHSA-7488-6r32-c95q, PYSEC-2026-3479

Key Facts

Patch immediately
  • CVE-2026-59822 is a high-severity vulnerability (CVSS 8.8 v4) affecting LiteLLM, airflow-3 (minimos), seal-litellm.
  • It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Jul 8, 2026. Public exploit code is available.
  • EPSS estimates a 0.8% probability of exploitation in the next 30 days.
  • Fixed versions are available, including airflow-3 3.3.1-r0, LiteLLM 1.80.11+sp999, LiteLLM 1.84.0.
  • Brandefense priority: patch immediately, because it is listed as exploited in the wild.

CVSS v4

8.8

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

EPSS (30-day exploit likelihood)

0.8%

Exploited in the wild

Yes

4 catalog listings

Public exploit code

Available

Proof-of-concept or weaponized module

Get the full CVE-2026-59822 brief as a PDF

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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.

Known-Exploited Catalog Listings

CatalogAddedRemediation dueRansomware use
CISA KEVSep 2, 2026Sep 16, 2026Not reported
Industry KEV feedJul 8, 2026Sep 16, 2026Not reported
CIRCL KEVSep 2, 2026Sep 16, 2026Not reported
ENISA EUVDSep 2, 2026n/aNot reported

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.

Affected Products

7 affected entries in total
ProductAffected versionsFixed in
LiteLLMLitellm>= < 1.84.01.84.0
airflow-3minimosSee advisory3.3.1-r0
seal-litellmsealSee advisory1.80.11+sp999

Patched Releases

airflow-3

3.3.1-r0

LiteLLM

1.80.11+sp999, 1.84.0

seal-litellm

1.80.11+sp999

Timeline

  1. Publicly disclosed

    Jul 8, 2026

  2. Added to Industry KEV feed

    Jul 8, 2026

  3. Added to CISA KEV

    Sep 2, 2026

  4. Added to CIRCL KEV

    Sep 2, 2026

  5. Added to ENISA EUVD

    Sep 2, 2026

  6. Last updated

    Sep 10, 2026

Weakness Type

  • CWE-287 Improper Authentication
  • CWE-303 Incorrect Implementation of Authentication Algorithm
  • CWE-306 Missing Authentication for Critical Function

References

12 more references in the full CVE brief

FAQ

Common Questions.

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