CVE-2026-55166 PUBLISHED

Lemur: any SSO-authenticated user achieves AWS IAM compromise and permanent PKI key access via ACME acme_url SSRF and creator-equality IDOR

Assigner: GitHub_M
Reserved: 16.06.2026 Published: 18.08.2026 Updated: 18.08.2026

Lemur manages TLS certificate creation. Prior to 1.9.2, authenticated users could influence an ACME authority acme_url without an effective server-side destination restriction and trigger AcmeHandler.setup_acme_client to make backend requests. An attacker could target cloud instance metadata or internal services from Lemur network context, potentially obtaining credentials available to the host. The advisory also identifies creator-equality authorization behavior that could preserve access to certificate key material after ownership or role changes, with insufficient export_private_key audit context to distinguish that access path. Together, the acme_url server-side request forgery and authorization weakness could expose cloud credentials and long-lived PKI private-key access. The fix adds ACME_DIRECTORY_HOST_ALLOWLIST validation and enriches key-export audit events with creator and current-owner context. This issue is fixed in version 1.9.2.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L
CVSS Score: 9.9

Product Status

Vendor Netflix
Product lemur
Versions
  • Version < 1.9.2 is affected

References

Problem Types

  • CWE-285: Improper Authorization CWE
  • CWE-639: Authorization Bypass Through User-Controlled Key CWE
  • CWE-918: Server-Side Request Forgery (SSRF) CWE