Vulnerability Description
Lemur manages TLS certificate creation. Prior to 1.9.1, StrictRolePermission and AuthorityCreatorPermission in lemur/auth/permissions.py call flask_principal.Permission.__init__() with zero Need objects when ADMIN_ONLY_AUTHORITY_CREATION and LEMUR_STRICT_ROLE_ENFORCEMENT are unset because both flags default to False. Flask-Principal Permission.allows() returns True when self.needs is empty, so the .can() authorization gate permits every authenticated identity, including the read-only role. A read-only user can access POST /api/1/authorities, POST /api/1/certificates/upload, POST /api/1/pending_certificates//upload, POST /api/1/notifications, PUT or DELETE /api/1/notifications/, and POST /api/1/domains to create root Certificate Authorities, upload arbitrary certificates, create or edit notifications that reach an SSRF sink, and create domain entries. Explicitly setting either flag to False continues to opt into the permissive behavior. This issue is fixed in version 1.9.1.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/Netflix/lemur/commit/e6a41e2c1b2028840d19039b06895524a19ad36f
- https://github.com/Netflix/lemur/releases/tag/v1.9.1
- https://github.com/Netflix/lemur/security/advisories/GHSA-qcqw-jwxc-2hqg
FAQ
What is CVE-2026-48508?
CVE-2026-48508 is a vulnerability with a CVSS score of 8.8 (HIGH). Lemur manages TLS certificate creation. Prior to 1.9.1, StrictRolePermission and AuthorityCreatorPermission in lemur/auth/permissions.py call flask_principal.Permission.__init__() with zero Need objec...
How severe is CVE-2026-48508?
CVE-2026-48508 has been rated HIGH with a CVSS base score of 8.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-48508?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.