CVE-2026-71308

HIGH

MEDIUM Priority: 0.03 BB Relevance: 66/100

Published: 2026-08-18 Modified: 2026-10-22 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Interaction Integ. Impact

CVSS Vector Breakdown

AV: Network

AC: Low

PR: Low

UI: None

S: Unchanged

C: None

I: High

A: High

Description

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.