Milvus: Unauthenticated Access to Restful API on Metrics Port (9091) Leads to Critical System Compromise

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

9.8 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2026-26190: 39.26% estimated exploitation activity in the next 30 days; percentile 98.60 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary Milvus exposes TCP port 9091 by default with two critical authentication bypass vulnerabilities: 1. The /expr debug endpoint uses a weak, predictable default authentication token derived from etcd.rootPath (default: by-dev), enabling arbitrary expression evaluation. 2. 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. Details Vulnerability 1: Weak Default Authentication on /expr Endpoint The /expr endpoint on port 9091 accepts an auth parameter that defaults to the etcd.rootPath value (by-dev). This value is well-known and predictable. An attacker who can reach port 9091 can evaluate arbitrary internal Go expressions, leading to: - Information/Credential Disclosure: Reading internal configuration values (MinIO secrets, etcd credentials) and user credential hashes via param.MinioCfg.SecretAccessKey.GetValue(),…

Published by the source

11 Feb 2026, 19:49 UTC

Last modified by the source

22 Oct 2026, 18:19 UTC

Source last checked

26 Oct 2026, 15:32 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-7ppg-37fh-vcr6

2. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-7ppg-37fh-vcr6

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# Patch Next advisory brief: CVE-2026-26190

Advisory: Milvus: Unauthenticated Access to Restful API on Metrics Port (9091) Leads to Critical System Compromise
IDs: CVE-2026-26190, GHSA-7ppg-37fh-vcr6
Record: https://patchnext.com/advisories/cve-2026-26190 (revision 2, source checked 26 Oct 2026, 15:32 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/milvus-io/milvus 2.6.10, 2.5.27. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/milvus-io/milvus: affected < 2.5.27; >= 2.6.0, < 2.6.10; fixed in 2.5.27, 2.6.10

## Suggested inspection (read-only)
- Go github.com/milvus-io/milvus: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/milvus-io/milvus.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-7ppg-37fh-vcr6 (GitHub-reviewed advisory GHSA-7ppg-37fh-vcr6 lists affected ranges: Go github.com/milvus-io/milvus >=0 =2.6.0 <2.6.10)

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