BerriAI litellm MCP Proxy user_api_key_auth_mcp.py UserAPIKeyAuth improper authentication
Summary
| CVE | CVE-2026-12773 |
|---|---|
| State | PUBLISHED |
| Assigner | VulDB |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-06-21 04:16:28 UTC |
| Updated | 2026-06-30 03:17:13 UTC |
| Description | A weakness has been identified in BerriAI litellm up to 1.59.8. Affected is the function UserAPIKeyAuth of the file litellm/proxy/_experimental/mcp_server/auth/user_api_key_auth_mcp.py of the component MCP Proxy. Executing a manipulation can lead to improper authentication. The attack may be launched remotely. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure. |
Risk And Classification
Primary CVSS: v4.0 5.5 MEDIUM from [email protected]
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/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
EPSS: 0.006120000 probability, percentile 0.449600000 (date 2026-07-04)
Problem Types: CWE-287 | CWE-303 | CWE-287 Improper Authentication | CWE-303 Incorrect Implementation of Authentication Algorithm
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 5.5 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/C... |
| 4.0 | CNA | DECLARED | 6.9 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P |
| 3.1 | [email protected] | Primary | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | ADP | CVSS | 7.3 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L |
| 3.1 | [email protected] | Secondary | 7.3 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L |
| 3.1 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | Secondary | 7.3 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L |
| 3.1 | CNA | DECLARED | 7.3 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:R |
| 3.0 | CNA | DECLARED | 7.3 | HIGH | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:R |
| 2.0 | [email protected] | Secondary | 7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P | |
| 2.0 | CNA | DECLARED | 7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P/E:POC/RL:ND/RC:UR |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
NonePrivileges Required
NoneUser Interaction
NoneConfidentiality
LowIntegrity
LowAvailability
LowSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/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
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v3.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
LowIntegrity
LowAvailability
LowCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:R
NVD Known Affected Configurations (CPE 2.3)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | BerriAI | Litellm | affected 1.59.0 | Not specified |
| CNA | BerriAI | Litellm | affected 1.59.1 | Not specified |
| CNA | BerriAI | Litellm | affected 1.59.2 | Not specified |
| CNA | BerriAI | Litellm | affected 1.59.3 | Not specified |
| CNA | BerriAI | Litellm | affected 1.59.4 | Not specified |
| CNA | BerriAI | Litellm | affected 1.59.5 | Not specified |
| CNA | BerriAI | Litellm | affected 1.59.6 | Not specified |
| CNA | BerriAI | Litellm | affected 1.59.7 | Not specified |
| CNA | BerriAI | Litellm | affected 1.59.8 | Not specified |
| ADP | Red Hat | Exploit Intelligence | Not specified | Not specified |
| ADP | Red Hat | Red Hat Ansible Automation Platform 2 | Not specified | Not specified |
| ADP | Red Hat | Red Hat OpenShift AI RHOAI | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| vuldb.com/vuln/372515/cti | [email protected] | vuldb.com | Permissions Required, VDB Entry |
| vuldb.com/vuln/372515 | [email protected] | vuldb.com | Third Party Advisory, VDB Entry |
| gist.github.com/YLChen-007/3cfaad10a69d7a15e4d4d458cb53309e | [email protected] | gist.github.com | Exploit, Third Party Advisory |
| vuldb.com/cve/CVE-2026-12773 | [email protected] | vuldb.com | Third Party Advisory, VDB Entry |
| bugzilla.redhat.com/show_bug.cgi | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | bugzilla.redhat.com | |
| security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12773.json | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | security.access.redhat.com | |
| access.redhat.com/security/cve/CVE-2026-12773 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| vuldb.com/submit/811282 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | vuldb.com | Exploit, Third Party Advisory, VDB Entry |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Eric-c (VulDB User) (en)
CNA: VulDB CNA Team (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-06-20T00:00:00.000Z | Advisory disclosed |
| CNA | 2026-06-20T02:00:00.000Z | VulDB entry created |
| CNA | 2026-06-20T11:31:42.000Z | VulDB entry last update |
| ADP | 2026-06-21T04:00:49.686Z | Reported to Red Hat. |
| ADP | 2026-06-21T03:15:08.647Z | Made public. |
Workarounds
ADP: Upgrade to litellm 1.81.16 or later. As a workaround, do not configure backend MCP servers with allow_all_keys: true, and restrict network access to the LiteLLM MCP proxy endpoints.
There are currently no legacy QID mappings associated with this CVE.