CVE-2026-48508

HIGHCVSS 8.8/10EPSS 0.24%

Last modified

CVE-2026-48508 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. 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. EPSS estimates a 0.24% chance of exploitation in the next 30 days.

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.

Metrics

EPSS Probability
0.24%

14.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
Netflixlemur< 1.9.1

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-48508?
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.
How severe is CVE-2026-48508?
CVE-2026-48508 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 0.24% probability of exploitation in the next 30 days.
How do I fix CVE-2026-48508?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST