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NVD / CVE Program· CNA GitHub_M

CVE-2026-42271: LiteLLM: Authenticated command execution via MCP stdio test endpoints

Noroxi assessment

Priority: Now (action score 91/100)

  • CISA has confirmed exploitation in the wild (Jun 8, 2026). Remediation deadline for US federal agencies: Jun 22, 2026.
  • A ready-made attack module is public (Metasploit, Nuclei); exploiting it takes no special expertise.
  • Probability of exploitation in the next 30 days: 91.4% (FIRST EPSS); higher than 99.8% of all records.
  • Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: BerriAI litellm 1.83.7.

Patch today or shut off access. Upgrade to BerriAI litellm 1.83.7 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS

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.

HighCVSS 8.7 · v4.0KEVWeaponized Fix available
Published
May 8, 2026
Updated
Oct 26, 2026
EPSS
91.4% · 99th percentile

Report tools

JSON

Action score

91

Now

Patch today or shut off access.

CVSS
34 / 40 · 8.7 / 10
CISA KEV
30 / 30 · Listed
EPSS
27 / 30 · 91.4%

CISA SSVC decision

Exploitation
active
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
8.7
NVD has not scored this yet; the score shown is the CNA’s.

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on Jun 8, 2026. That signals real attacks, not theory.

Remediation deadline for US federal agencies: Jun 22, 2026.

Get told when this record changes

  • In CISA KEV: exploitation in the wild confirmed
  • Weaponized exploit exists
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-42271

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
litellmlitellm
redhatopenshift ai

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • litellm litellm1.74.2 and later · before 1.83.7
  • redhat openshift ai2.25 and later · before 2.25.8
  • redhat openshift ai3.3 and later · before 3.3.4
  • redhat openshift ai3.4

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • BerriAI litellm

    • >= 1.74.2, < 1.83.7affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
PyPIlitellmfrom 1.74.2 · before 1.83.71.83.7

Same product

litellm: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-42208LiteLLM: SQL injection in Proxy API key verificationKEV
    94Now
  • CVE-2026-59822LiteLLM: MCP Authentication Bypass via OAuth2 Passthrough FallbackKEV
    65This week
  • CVE-2026-35029LiteLLM affected by privilege escalation via unrestricted proxy configuration endpoint
    46Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-40217Apr 10, 2026 · LiteLLM through 2026-04-08 allows remote attackers to execute arbitrary code via bytecode rewriting at the /guardrails/test_custom_code URI.
    40Plan
  • ← EarlierCVE-2026-42203May 8, 2026 · LiteLLM: Server-Side Template Injection in /prompts/test endpoint
    34Monitor
  • Later →CVE-2026-47101May 21, 2026 · LiteLLM < 1.83.14 Privilege Escalation via API Key Generation
    34Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
BerriAI litellm1.83.7 · descriptionVendor (CNA)
PyPI:litellm1.83.7Package registry (OSV)

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

  • Metasploit module ×1
  • Nuclei detection template ×1
  • Proof-of-concept repository on GitHub ×2

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Metasploit moduleexploit/multi/http/litellm_mcp_test_cmd_injectionBerriAI LiteLLM Proxy MCP Test Endpoint Command Executionexploit2026-04-21
Nuclei detection templateNuclei template CVE-2026-42271 —
Proof-of-concept repository on GitHubstars:12026-05-20
Proof-of-concept repository on GitHubstars:02026-06-09

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Metasploit-17 d
  2. Published
  3. First PoC+12 d
  4. CISA KEV+31 d
  5. TodayOct 29, 2026+174 d
EPSS, last 120 days-1% in 7 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

—

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

  • CVE-2026-3503032 days apartLiteLLM has an authentication bypass via OIDC userinfo cache key collision
    37Monitor

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
X

Weakness class (CWE)

CWE-77 · Improper Neutralization of Special Elements used in a Command ('Command Injection')

CVSS vector

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (8 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records