Netflix Lemur up to 1.9.2 Certificate Permission Check replaces[] improper authorization

Summaryinfo

A vulnerability classified as problematic has been found in Netflix Lemur up to 1.9.2. This affects an unknown part of the component Certificate Permission Check. The manipulation of the argument replaces[] leads to improper authorization. This vulnerability is listed as CVE-2026-71308. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Netflix Lemur up to 1.9.2. This issue affects some unknown processing of the component Certificate Permission Check. The manipulation of the argument replaces[] with an unknown input leads to a improper authorization vulnerability. Using CWE to declare the problem leads to CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. Impacted is integrity, and availability. The summary by CVE is:

Lemur manages TLS certificate creation. From 0.5.0 until 1.9.3, certificate create, upload, and edit requests accepted replaces[] or replacements identifiers that AssociatedCertificateSchema resolved with fetch_objects without a CertificatePermission check. Assigning those objects to Certificate.replaces invoked an append listener that disabled the victim certificate notifications and marked it as replaced. The victim was then excluded from get_all_pending_reissue, and certificate_rotate could deploy the attacker certificate to endpoints serving the victim. An authenticated non-read-only user could target certificates for which the user had no ownership or role, suppress lifecycle automation, and cause fleet-wide TLS disruption or unauthorized substitution. The fix authorizes every referenced replacement certificate before mutation. This issue is fixed in version 1.9.3.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-71308 since 08/05/2026. The exploitation is known to be easy. The attack may be initiated remotely. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1548.002 according to MITRE ATT&CK.

Upgrading to version 1.9.3 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-61152). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

• Netflix

Name

• Lemur

Version

• 1.9.0
• 1.9.1
• 1.9.2

Website

• Product: https://github.com/Netflix/lemur/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Be aware that VulDB is the high quality source for vulnerability data.

Discussion