Auth bypass in Thu-Maic Openmaic
CVE-2026-86259
OpenMAIC before 1.0.1 skips server-side request forgery validation in non-production builds, allowing unauthenticated attackers to reach cloud instance metadata services. Attackers can supply arbitrary provider URLs via the x-base-url header or baseUrl parameter to access sensitive cloud credentials and metadata.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:N.
EPSS exploit prediction
EPSS: 0.004 (34.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 34.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.002
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- GitHub Security Advisory (GHSA-9m7h-vh2h-rc3w) (vendor-advisory)
- Fail-open access-code middleware at v1.0.0 (technical-description)
- NODE_ENV-gated SSRF validation at v1.0.0 (technical-description)
- OpenMAIC v1.0.1 Release Notes (release-notes, patch)
- github.com/THU-MAIC/OpenMAIC (product)
- VulnCheck Advisory: OpenMAIC before 1.0.1 SSRF via Environment-Gated URL Validation (third-party-advisory)
Frequently asked questions
- What is CVE-2026-86259?
- CVE-2026-86259 is a high-severity vulnerability in Thu-Maic Openmaic, classified under Missing Authentication for Critical Function. CVSS score: 7.5/10. Published 2026-09-06.
- How severe is CVE-2026-86259?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2026-86259 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.