BerriAI LiteLLM Improper Authentication Vulnerability (CVE-2026-59822)
Severity: high · Patch status: patched · Since 2026-09-02 · CVE-2026-59822
BerriAI LiteLLM contains an improper authentication vulnerability in the MCP Streamable HTTP endpoint that could allow an unauthenticated attacker to establish an authenticated MCP session using an arbitrary Bearer token. CISA added CVE-2026-59822 to its Known Exploited Vulnerabilities catalog on Sep 2, 2026, which means attackers are exploiting it in the wild.
What to do
- Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
- US federal agencies must remediate by Sep 16, 2026 (BOD 22-01); treat that as the outer limit.
Sources
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