CVE-2026-71417

Lemur: Any user can revoke arbitrary certificates at the CA by uploading a duplicate record and revoking it

Published Aug 18, 2026 CVSS 3.1 · 7.3 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-pxmc-2ffp-8j67 Lemur: Any user can revoke arbitrary certificates at the CA by uploading a duplicate record and revoking it
History
Type Values Removed Values Added
First Time appeared Netflix
Netflix lemur
Vendors & Products Netflix
Netflix lemur
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values 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.
Title Lemur: Any user can revoke arbitrary certificates at the CA by uploading a duplicate record and revoking it
Weaknesses CWE-639
References
Metrics cvssV3_1

{'score': 7.3, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Aug 18, 2026, 7:47 PM
Reserved
Aug 6, 2026, 4:28 PM
Status
Deferred
Published
Aug 18, 2026, 8:17 PM
Modified
Oct 22, 2026, 10:10 PM