What is CVE-2026-42271?

CVE-2026-42271 is a high-severity vulnerability in Berriai Litellm, classified under Command Injection. CVSS score: 8.8/10. Published 2026-05-08.

How severe is CVE-2026-42271?

High severity. CVSS v3 base score is 8.8 out of 10.

Is CVE-2026-42271 known to be exploited?

Yes. CVE-2026-42271 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-06-08), indicating it is being actively exploited. 3 public proof-of-concept repositories are indexed.

RCE in Berriai Litellm

CVE-2026-42271

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…

Vulnerability class: Command Injection (OS Command Injection)

EPSS: 0.802 (99.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Berriai Litellm — versions >= 1.74.2, < 1.83.7
Litellm
Redhat Openshift_ai — versions 3.4

Weakness classification (CWE)

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2026-06-08. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2026-06-22.

Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Public proof-of-concept exploits

References

security-advisories@github.com (x_refsource_CONFIRM, Patch, Mitigation, Vendor Advisory)
security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)
0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Third Party Advisory)
0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Third Party Advisory)
0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Third Party Advisory)
0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Third Party Advisory)
0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Third Party Advisory)
0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Third Party Advisory)

Frequently asked questions

What is CVE-2026-42271?: CVE-2026-42271 is a high-severity vulnerability in Berriai Litellm, classified under Command Injection. CVSS score: 8.8/10. Published 2026-05-08.
How severe is CVE-2026-42271?: High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2026-42271 known to be exploited?: Yes. CVE-2026-42271 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-06-08), indicating it is being actively exploited. 3 public proof-of-concept repositories are indexed.