Auth bypass in Berriai Litellm

CVE-2026-12771

A vulnerability was identified in BerriAI litellm up to 1.82.2. This affects an unknown function of the file litellm/proxy/auth/user_api_key_auth.py of the component M2M JWT Handler. Such manipulation leads to improper authorization. The attack can be launched remotely. A high complexity level is associated with this attack. The exploitability is reported as difficult. The exploit is publicly available and might be used. The vendor was contacted early about this disclosure.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.0 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.004 (34.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 34.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-12771: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-12771?
CVE-2026-12771 is a medium-severity vulnerability in Berriai Litellm, classified under Incorrect Privilege Assignment. CVSS score: 5.0/10. Published 2026-06-21.
How severe is CVE-2026-12771?
Medium severity. CVSS v3 base score is 5.0 out of 10.