CVE entry · CVE-2026-59822
CVE-2026-59822: BerriAI LiteLLM Improper Authentication Vulnerability
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.
- Actively exploited: added to CISA’s KEV catalog on September 2, 2026.
- Use by ransomware: not established so far.
- Remediation deadline for US federal agencies: September 16, 2026.
Description from CISA’s KEV catalog.
What to do
- Check whether your estate includes BerriAI LiteLLM, including internet-facing devices.
- Apply the vendor’s patch or mitigations (references below). Failing that, isolate the product or stop using it, as CISA requires of US federal agencies.
- An exploited vulnerability has often been used before it was fixed: look for signs of compromise, especially on internet-facing devices.