LiteLLM has an authentication bypass via OIDC userinfo cache key collision
Summary
| CVE | CVE-2026-35030 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-06 17:17:12 UTC |
| Updated | 2026-06-30 03:19:01 UTC |
| Description | LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. Prior to 1.83.0, when JWT authentication is enabled (enable_jwt_auth: true), the OIDC userinfo cache uses token[:20] as the cache key. JWT headers produced by the same signing algorithm generate identical first 20 characters. This configuration option is not enabled by default. Most instances are not affected. An unauthenticated attacker can craft a token whose first 20 characters match a legitimate user's cached token. On cache hit, the attacker inherits the legitimate user's identity and permissions. This affects deployments with JWT/OIDC authentication enabled. Fixed in v1.83.0. |
Risk And Classification
Primary CVSS: v4.0 9.4 CRITICAL from [email protected]
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/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
EPSS: 0.004900000 probability, percentile 0.385720000 (date 2026-07-02)
Problem Types: CWE-287 | CWE-222 | CWE-287 CWE-287: Improper Authentication | CWE-222 Truncation of Security-relevant Information
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 9.4 | CRITICAL | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:X/C... |
| 4.0 | CNA | DECLARED | 9.4 | CRITICAL | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N |
| 3.1 | ADP | DECLARED | 9.1 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
| 3.1 | ADP | CVSS | 9.1 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
| 3.1 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | Secondary | 9.1 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
| 3.1 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | Secondary | 9.1 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
CVSS v4.0 Breakdown
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/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
CVSS v3.1 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
NVD Known Affected Configurations (CPE 2.3)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | BerriAI | Litellm | affected < 1.83.0 | Not specified |
| ADP | Red Hat | Red Hat Ansible Automation Platform 2.6 | Not specified | Not specified |
| ADP | Red Hat | Red Hat OpenShift AI 2.25 | Not specified | Not specified |
| ADP | Red Hat | Red Hat OpenShift AI 3.3 | Not specified | Not specified |
| ADP | Red Hat | Lightspeed Core | Not specified | Not specified |
| ADP | Red Hat | Red Hat OpenShift AI RHOAI | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/errata/RHSA-2026:28960 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/security/cve/CVE-2026-35030 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-35030.json | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | security.access.redhat.com | |
| github.com/BerriAI/litellm/security/advisories/GHSA-jjhc-v7c2-5hh6 | [email protected] | github.com | Mitigation, Vendor Advisory |
| access.redhat.com/errata/RHSA-2026:30056 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| bugzilla.redhat.com/show_bug.cgi | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | bugzilla.redhat.com | |
| access.redhat.com/errata/RHSA-2026:13545 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| ADP | 2026-04-06T18:01:07.517Z | Reported to Red Hat. |
| ADP | 2026-04-06T16:47:02.065Z | Made public. |
Solutions
ADP: RHSA-2026:13545: Red Hat Ansible Automation Platform 2.6
ADP: RHSA-2026:28960: Red Hat OpenShift AI 2.25
ADP: RHSA-2026:30056: Red Hat OpenShift AI 3.3
Workarounds
ADP: To mitigate this issue, ensure that JWT authentication is not enabled in LiteLLM configurations. The vulnerability only manifests when `enable_jwt_auth` is set to `true`. If JWT authentication is not strictly required, disable it to prevent potential authentication bypass and privilege escalation. If this configuration is changed, a restart of the LiteLLM service may be required for the changes to take effect.