Authentication Bypass in litellm (CVE-2026-35030)
Summary
Authentication bypass in litellm (CVE-2026-35030). Confidential information can be exposed externally. Mitigation: upgrade to 1.83.0 or later.
Original description
The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-35030 has been found in litellm.
Confidential information can be exposed externally. CVSS score: 9.1/10.
What to do: upgrade litellm to 1.83.0 or later.
If unsure, ask your IT team or search "litellm CVE-2026-35030" on the vendor's site.
CVE-2026-35030 (litellm) — CWE-287 / CVSS v3 9.1
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 1.83.0 — apply immediately
Workaround: Disable OIDC userinfo caching by setting the cache TTL to 0, or disable JWT authentication entirely.
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Authentication bypass (CWE-287) exists in litellm.
Check the vendor advisory for the affected versions of litellm.
Severity: Critical (CVSS 9.1/10). Confidential information can be exposed externally.
Update to 1.83.0.
Workaround: Disable OIDC userinfo caching by setting the cache TTL to 0, or disable JWT authentication entirely.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'litellm' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'litellm' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
litellmを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply temporary workaround mitigate
Disable OIDC userinfo caching by setting the cache TTL to 0, or disable JWT authentication entirely.パッチが適用されるまでの応急処置として、Disable OIDC userinfo caching by setting the cache TTL to 0, or disable JWT authentication entirely. を実施。回避策の副作用 (機能低下) を確認した上で。
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3Apply patch patch
Upgrade litellm to 1.83.0ステージング環境で 1.83.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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4Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory nvd.nist.gov
- advisory github.com
- advisory github.com
- package github.com
- package pypi.org
- report bugzilla.redhat.com
- web security.access.redhat.com