Auth bypass in Netflix Lemur
CVE-2026-55163
Lemur manages TLS certificate creation. Prior to 1.9.2, PUT /api/1/roles/ in lemur/roles/views.py:298 authorized updates with RoleMemberPermission(role_id), which allowed either an administrator or any existing member of the target role. The handler passed data["users"] and data["name"] to service.update, allowing a non-admin member to add or remove other users and rename the role. This enabled lateral privilege grants within roles that control certificate and authority access and could deny access by removing legitimate members. The DELETE handler already required admin_permission, confirming that the weaker PUT authorization was inconsistent. The fix applies the same administrator-only requirement to the PUT handler. This issue is fixed in version 1.9.2.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.002 (10.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 11th percentile — 10.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.001
Affected products
- Netflix Lemur — versions < 1.9.2
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-55163?
- CVE-2026-55163 is a medium-severity vulnerability in Netflix Lemur, classified under Incorrect Authorization. CVSS score: 6.3/10. Published 2026-08-18.
- How severe is CVE-2026-55163?
- Medium severity. CVSS v3 base score is 6.3 out of 10.