Auth bypass in Milvus
CVE-2026-26190
Milvus is an open-source vector database built for generative AI applications. Prior to 2.5.27 and 2.6.10, Milvus exposes TCP port 9091 by default, which enables authentication bypasses. The /expr debug endpoint uses a weak, predictable default authentication token derived from etcd.rootPath (default: by-dev), enabling arbitrary expression evaluation. The full REST API (/api/v1/*) is registered on the metrics/management port without any authentication, allowing unauthenticated access to all business operations including data manipulation and credential management. This vulnerability is fixed in 2.5.27 and 2.6.10.
Vulnerability class: Broken Authentication
EPSS: 0.369 (98.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Milvus
- Milvus-io Milvus — versions < 2.5.27, >= 2.6.0, < 2.6.10
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Mitigation, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-26190?
- CVE-2026-26190 is a critical-severity vulnerability in Milvus, classified under Missing Authentication for Critical Function. CVSS score: 9.8/10. Published 2026-02-13.
- How severe is CVE-2026-26190?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2026-26190 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.