CVE-2026-42271
LiteLLM: Authenticated command execution via MCP stdio test endpoints
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/SA:N
Description
LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. From version 1.74.2 to before version 1.83.7, two endpoints used to preview an MCP server before saving it — POST /mcp-rest/test/connection and POST /mcp-rest/test/tools/list — accepted a full server configuration in the request body, including the command, args, and env fields used by the stdio transport. When called with a stdio configuration, the endpoints attempted to connect, which spawned the supplied command as a subprocess on the proxy host with the privileges of the proxy process. The endpoints were gated only by a valid proxy API key, with no role check. Any authenticated user — including holders of low-privilege internal-user keys — could therefore run arbitrary commands on the host. This issue has been patched in version 1.83.7.
Official description from the CVE record, published by GitHub_M. Copyright © 1999-2026 The MITRE Corporation. See /security/cve/legal for the CVE license. View the record on cve.org
Key data
CVSS 4.0 High 8.7
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/SA:N
Attack vector: Network
The vulnerable component can be reached over a network, possibly from the Internet.
Attack complexity: Low
No measurable action is needed to get around the system's built-in security controls. The attack is repeatable.
Attack requirements: Present
The attack depends on certain deployment or execution conditions being present.
Privileges required: Low
A basic user account is needed.
User interaction: None
No action from any user is needed.
Vulnerable system: confidentiality: High
Serious or total effect on the secrecy of data.
Vulnerable system: integrity: High
Serious or total effect on the trustworthiness of data.
Vulnerable system: availability: High
Serious or total effect on availability.
Subsequent systems: confidentiality: High
Serious or total effect on other systems' data secrecy.
Subsequent systems: integrity: None
No effect on other systems' data trustworthiness.
Subsequent systems: availability: None
No effect on other systems' availability.
| Metric | Value | What it means |
|---|---|---|
| Attack vector | Network | The vulnerable component can be reached over a network, possibly from the Internet. |
| Attack complexity | Low | No measurable action is needed to get around the system's built-in security controls. The attack is repeatable. |
| Attack requirements | Present | The attack depends on certain deployment or execution conditions being present. |
| Privileges required | Low | A basic user account is needed. |
| User interaction | None | No action from any user is needed. |
| Vulnerable system: confidentiality | High | Serious or total effect on the secrecy of data. |
| Vulnerable system: integrity | High | Serious or total effect on the trustworthiness of data. |
| Vulnerable system: availability | High | Serious or total effect on availability. |
| Subsequent systems: confidentiality | High | Serious or total effect on other systems' data secrecy. |
| Subsequent systems: integrity | None | No effect on other systems' data trustworthiness. |
| Subsequent systems: availability | None | No effect on other systems' availability. |
CVSS 3.1 High 8.8
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector: Network
The vulnerable component can be reached over a network, possibly from the Internet.
Attack complexity: Low
No special conditions are needed. The attack can be repeated at will.
Privileges required: Low
A basic user account is needed.
User interaction: None
No action from any user is needed.
Scope: Unchanged
The impact stays within the vulnerable component.
Confidentiality impact: High
Serious or total effect on the secrecy of data.
Integrity impact: High
Serious or total effect on the trustworthiness of data.
Availability impact: High
Serious or total effect on availability.
| Metric | Value | What it means |
|---|---|---|
| Attack vector | Network | The vulnerable component can be reached over a network, possibly from the Internet. |
| Attack complexity | Low | No special conditions are needed. The attack can be repeated at will. |
| Privileges required | Low | A basic user account is needed. |
| User interaction | None | No action from any user is needed. |
| Scope | Unchanged | The impact stays within the vulnerable component. |
| Confidentiality impact | High | Serious or total effect on the secrecy of data. |
| Integrity impact | High | Serious or total effect on the trustworthiness of data. |
| Availability impact | High | Serious or total effect on availability. |
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EPSS
- Score
- 0.91445 (91.4% probability)
- Percentile
- 99.8%
- Scores of
- Nov 10, 2026
- Model
- v2026.06.15
CISA Known Exploited Vulnerabilities
- Name in the catalog
- BerriAI LiteLLM Command Injection Vulnerability
- Added to the catalog
- Jun 8, 2026
- Federal due date
- Jun 22, 2026
CISA assessment as of May 8, 2026
- Exploitation
- Recorded by CISA as active
- Automatable
- no
- Technical impact
- total
Weakness (CWE)
Affected products
BerriAI litellm
- affected: >= 1.74.2, < 1.83.7
References
Timeline
- ID reserved
- Record published
- Added to CISA KEV
- Record last updated
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Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:50 UTC. Sources and licenses