CVE-2026-59822: BerriAI LiteLLM Improper Authentication Vulnerability

Patch now

HIGH 8.2EXPLOITEDREMOTEUPGRADE

CVE-2026-59822 is a high-severity flaw (CVSS 8.2) affecting litellm, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

High severity
Exploited in the wild (CISA KEV)
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	8.2 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.8% (top 43%)
CISA exploited list	Yes, fix due 2026-09-16
Weakness	CWE-287, CWE-306
Published	2026-07-08
Last modified	2026-09-03

Publisher (CNA): GitHub, Inc. · Vendor: litellm

Am I affected?

Timeline

2026-07-08 20:16 UTCPublished CVE record published
2026-09-02Exploited Added to the CISA Known Exploited Vulnerabilities list
2026-09-03 13:05 UTCUpdated Record last modified
2026-09-16Deadline CISA due date for US federal agencies to patch

litellm litellm UPGRADE

Affected: < 1.84.0

Fixed in: 1.84.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy litellm || rpm -q litellm || litellm --version

2. UPGRADE to 1.84.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade litellm

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade litellm

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Exact fixes by distribution

Python (pip) · litellm · FIXED · 1.84.0 · vulnerable: < 1.84.0 · source

pip install --upgrade "litellm>=1.84.0" pip show litellm

Fedora 46 · retext · FIXED · 8.1.0-1.fc46 · FEDORA-2026-0602a84203 · source

sudo dnf upgrade --advisory=FEDORA-2026-0602a84203

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: HORKimhab/CVE-2026-59822 (0 stars)
Write-up: www.wiz.io/blog/ai-infrastructure-honeypot

Verify at the official source NVD · CVE Program · CISA KEV catalog · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-59822?

litellm: upgrade to 1.84.0. Exact commands for each OS are on this page.

Is CVE-2026-59822 being exploited?

Yes. CVE-2026-59822 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2026-59822 affect?

CVE-2026-59822 affects litellm. Severity is high (CVSS 8.2). 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

How urgent is CVE-2026-59822?

Priority 73/100. High severity; Exploited in the wild (CISA KEV); Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-35030 CRITICAL 9.1 UPGRADE LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format
CVE-2026-35029 HIGH 8.8 UPGRADE LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format

References

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