CVE-2026-71417
Lemur: Any user can revoke arbitrary certificates at the CA by uploading a duplicate record and revoking it
Description
Lemur manages TLS certificate creation. Prior to 1.9.3, POST /api/1/certificates/upload allowed a non-read-only user to create a duplicate row using another certificate body, authority_id, serial, or external_id without requiring permission on the underlying authority. PUT /api/1/certificates//revoke authorized the caller against only the selected Lemur row, so the creator of the duplicate bypassed CertificatePermission. The duplicate had no cert.endpoints, which also bypassed the safeguard that prevents revocation of deployed certificates. Issuer plugins then revoked the real CA-side certificate using certificate.body or external_id under the stored authority credentials. An attacker could therefore revoke arbitrary managed certificates and cause fleet-wide TLS denial of service. The fix rejects duplicate authority_id and serial identities, requires authority access on upload, and checks every matching row during revocation. This issue is fixed in version 1.9.3.
INFO
Published Date :
Aug. 18, 2026, 8:17 p.m.
Last Modified :
Oct. 22, 2026, 10:10 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | MITRE-CVE |
Solution
- Update Lemur to version 1.9.3.
- Validate certificate upload permissions.
- Ensure revocation checks authority access.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-71417.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-71417 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-71417
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-71417 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-71417 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Translated by [email protected]
Oct. 22, 2026
Action Type Old Value New Value Added Translation Title: lemur de Netflix, Description: Lemur gestiona la creación de certificados TLS. Antes de la versión 1.9.3, POST /API/1/certificates/upload permitía a un usuario no de solo lectura crear una fila duplicada utilizando otro cuerpo de certificado, authority_id, serial o external_id sin requerir permiso sobre la autoridad subyacente. PUT /API/1/certificates//revoke autorizaba al llamante solo contra la fila de Lemur seleccionada, por lo que el creador del duplicado eludía CertificatePermission. El duplicado no tenía cert.endpoints, lo que también eludía la salvaguarda que impide la revocación de certificados desplegados. Los plugins de emisor luego revocaban el certificado real del lado de la CA utilizando certificate.body o external_id bajo las credenciales de autoridad almacenadas. Un atacante podría, por lo tanto, revocar certificados gestionados arbitrarios y causar una denegación de servicio TLS en toda la flota. La solución rechaza identidades duplicadas de authority_id y serial, requiere acceso de autoridad en la carga y verifica cada fila coincidente durante la revocación. Este problema está solucionado en la versión 1.9.3. -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 18, 2026
Action Type Old Value New Value Added Reference https://github.com/Netflix/lemur/security/advisories/GHSA-pxmc-2ffp-8j67 Added SSVC {'id': 'CVE-2026-71417', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-18T19:47:37.666221Z'} -
New CVE Received by [email protected]
Aug. 18, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Netflix', 'product': 'lemur', 'versions': [{'status': 'affected', 'version': '< 1.9.3'}]}] Added Description Lemur manages TLS certificate creation. Prior to 1.9.3, POST /api/1/certificates/upload allowed a non-read-only user to create a duplicate row using another certificate body, authority_id, serial, or external_id without requiring permission on the underlying authority. PUT /api/1/certificates//revoke authorized the caller against only the selected Lemur row, so the creator of the duplicate bypassed CertificatePermission. The duplicate had no cert.endpoints, which also bypassed the safeguard that prevents revocation of deployed certificates. Issuer plugins then revoked the real CA-side certificate using certificate.body or external_id under the stored authority credentials. An attacker could therefore revoke arbitrary managed certificates and cause fleet-wide TLS denial of service. The fix rejects duplicate authority_id and serial identities, requires authority access on upload, and checks every matching row during revocation. This issue is fixed in version 1.9.3. Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:H Added CWE CWE-639 Added Reference https://github.com/Netflix/lemur/commit/851389ae737a6d6bf16c1f9ca64a2ce56c1cc5c6 Added Reference https://github.com/Netflix/lemur/releases/tag/v1.9.3 Added Reference https://github.com/Netflix/lemur/security/advisories/GHSA-pxmc-2ffp-8j67