---
id: CVE-2026-71308
title: Lemur manages TLS certificate creation
summary: >-
  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 Certific…
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H'
cwe:
  - CWE-639
  - CWE-862
vendor: lemur
product: lemur
affected:
  - 'lemur >= 0.5.0, <= 1.9.2'
patched:
  - lemur 1.9.3
published: '2026-08-18'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T21:02:26.047'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-71308'
references:
  - url: >-
      https://github.com/Netflix/lemur/commit/286874535160952143b0afe2d356642669f9d4c6
    label: security-advisories@github.com
  - url: 'https://github.com/Netflix/lemur/releases/tag/v1.9.3'
    label: security-advisories@github.com
  - url: 'https://github.com/Netflix/lemur/security/advisories/GHSA-cfh6-pv5c-38jv'
    label: security-advisories@github.com
  - url: 'https://github.com/Netflix/lemur/security/advisories/GHSA-cfh6-pv5c-38jv'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://github.com/advisories/GHSA-cfh6-pv5c-38jv'
tags:
  - nvd
  - ghsa
  - pip
epss: 0.00217
epssPercentile: 0.12395
aliases:
  - GHSA-cfh6-pv5c-38jv
ecosystem: pip
ingestedAt: '2026-08-18T21:22:59.688Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-71308)

Affected packages:

- `lemur >= 0.5.0, <= 1.9.2`

Patched in:

- `lemur 1.9.3`

Source: https://github.com/advisories/GHSA-cfh6-pv5c-38jv