CVE & CISA-KEV Catalog

CVE-2026-59822

HIGHCISA KEV
8.2
CVSS v3
NVD

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.

How to fix

Remediation Available
litellmNVD
Affected:< 1.84.0Fixed in:1.84.0CVE-2026-59822derived from NVD

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged

Impact

ConfidentialityHigh
IntegrityLow
AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

Exploit Intelligence

0.87%probability of exploitation in 30 days
57thpercentile

Moderate risk: more likely to be exploited than 57% of all known CVEs.

Known Exploited Vulnerability (CISA KEV)

Remediation due: 2026-09-16

References

Third-Party Advisory1
Government Resource1
Release Notes1

Related Vulnerabilities

Other CWE-287 (Improper Authentication) vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2023-35082Critical9.8100%KEV + RansomFix
CVE-2023-35078Critical9.8100%KEV + RansomFix
CVE-2017-7921Critical9.8100%KEV-
CVE-2024-7593Critical9.8100%KEV-
CVE-2023-46805High8.2100%KEV + Ransom-
CVE-2022-40684Critical9.8100%KEV + RansomFix

Common questions

How do I fix CVE-2026-59822?

Upgrade litellm to 1.84.0 or later.

Is CVE-2026-59822 being actively exploited?

Yes. CVE-2026-59822 is listed in the CISA Known Exploited Vulnerabilities catalog, which means exploitation has been observed in the wild. US federal agencies were required to remediate it by 2026-09-16. Treat it as a priority whatever its CVSS score says.

How severe is CVE-2026-59822?

CVE-2026-59822 has a CVSS v3 base score of 8.2, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-59822 affect?

Published advisories record a fix for litellm (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

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CVE-2026-59822 severity badge

Markdown

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This vulnerability is actively exploited in the wild

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-09-03.