MediumVulnerabilityLLM-specific

CVE-2026-84377: LiteLLM proxy credential exposure through unchecked api_base redirection

Source: NVD(opens in a new tab)
Identifier: CVE-2026-84377
Published: September 2, 2026
Record updated: October 9, 2026

Affected: litellm < 1.88.6, fixed in 1.88.6, released August 8, 2026, 24 days before disclosure
litellm >= 1.89.0, < 1.89.7, fixed in 1.89.7, released August 8, 2026, 24 days before disclosure
litellm >= 1.90.0, < 1.90.7, fixed in 1.90.7, released August 8, 2026, 24 days before disclosure
and 6 more
Known exploitation: Not listed in the CISA Known Exploited Vulnerabilities catalog at the last check.
EPSS: 0.5%

Summary

LiteLLM proxy versions before 1.88.6 and 1.96.2 contain CVE-2026-84377. Any authenticated proxy user could redirect an outbound provider call to a destination they control, causing the proxy to send its configured provider credentials there. Incomplete request validation in several litellm/proxy files let routing and credential parameters such as api_base, base_url and litellm_credential_name be applied without clearing the stored key, exposing upstream credentials and enabling server-side requests to internal services reachable by the proxy.

Mitigation

Fixed in 1.88.6 and 1.96.2.

Details

Scores and exploitation

CVSS score: 6.5(medium)
Patch available: Yes
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Attack vector: network
Attack complexity: low
Privileges required: low
User interaction: none
EPSS: 0.5%Estimated probability that this CVE is exploited in the next 30 days, from the FIRST Exploit Prediction Scoring System. Read on November 4, 2026.
Disclosure date: September 2, 2026

Weaknesses and techniques

Weakness (CWE): CWE-918
Attack pattern (CAPEC): CAPEC-664

Affected

Packages: litellm@< 1.88.6 (fixed: 1.88.6)
litellm@>= 1.89.0, < 1.89.7 (fixed: 1.89.7)
litellm@>= 1.90.0, < 1.90.7 (fixed: 1.90.7)
litellm@>= 1.91.0, < 1.91.5 (fixed: 1.91.5)
litellm@>= 1.92.0, < 1.92.2 (fixed: 1.92.2)
litellm@>= 1.93.0, < 1.93.2 (fixed: 1.93.2)
litellm@>= 1.94.0, < 1.94.3 (fixed: 1.94.3)
litellm@>= 1.95.0, < 1.95.1 (fixed: 1.95.1)
litellm@>= 1.96.0, < 1.96.2 (fixed: 1.96.2)

Classification

Attack type: Other
Attack sophistication: Moderate
AI component targeted: API
Impact: Confidentiality
Labels: security

How this record was produced

Summaries, mitigations and labels on this page are generated automatically from the source. The linked source is authoritative. The source gives this advisory a description and no title, so the title above is a headline generated from the source text.

Original source: https://nvd.nist.gov/vuln/detail/CVE-2026-84377

First tracked: September 2, 2026 at 08:07 PM ET, from NVD/CVE Database

Classifier: claude-haiku-5-5, prompt v4

Classifier confidence: 95% (self-assessed)

Affected packages in the Exposure Registry

Matched by package name and ecosystem. Each entry shows whether the package delegates to a language model and how many tracked packages depend on it.

litellmPyPILLM dependency since 2023-07-27 · 55 tracked dependents

Summary

Mitigation

Affected packages in the Exposure Registry

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