Vulnerability · Published Aug 18, 2026 · Assigned by GitHub_M

CVE-2026-55163Lemur: Privilege escalation via PUT /api/1/roles/<id> — non-admin role members can rewrite role membership

Medium 6.3

In plain English

A medium-severity incorrect authorization in lemur from Netflix. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.3Medium

Exploit odds (30 days)0.2%top 87.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	lemur	1.9.2	GHSA-x3vf-mgxj-7785
PyPI	lemur	1.9.2	PYSEC-2026-2591

Affected products (as reported)

Vendor	Product	Versions
Netflix	lemur	< 1.9.2

Weakness: CWE-863 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

References

https://github.com/Netflix/lemur/security/advisories/GHSA-x3vf-mgxj-7785 x_refsource_CONFIRM
https://github.com/Netflix/lemur/commit/9523a3b9cb3170ec9f795162b8c60e1ad3c4f9ce x_refsource_MISC
https://github.com/Netflix/lemur/releases/tag/v1.9.2 x_refsource_MISC