CVE-2026-71308Public exploitNetwork attack vector

Certificate substitution via unchecked replacement references

Published Aug 18, 2026 · Updated Aug 18, 2026

Missing authorization in certificate replacement handling in Netflix Lemur before 1.9.3 allows remote authenticated users to substitute certificates. AssociatedCertificateSchema resolves replaces and replacements identifiers to Certificate objects with fetch_objects, and the create, upload, and edit paths assign them to Certificate.replaces without enforcing CertificatePermission on each referenced certificate. Any non-read-only account can therefore target certificates outside its ownership or roles, silence expiration notifications, and let certificate_rotate push the attacker certificate to endpoints that served the victim certificate, causing TLS disruption or unauthorized substitution.

CVSS severity8.1
High
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authorization in certificate replacement handling in Netflix Lemur before 1.9.3 allows remote authenticated users to substitute certificates. AssociatedCertificateSchema resolves replaces and replacements identifiers to Certificate objects with fetch_objects, and the create, upload, and edit paths assign them to Certificate.replaces without enforcing CertificatePermission on each referenced certificate. Any non-read-only account can therefore target certificates outside its ownership or roles, silence expiration notifications, and let certificate_rotate push the attacker certificate to endpoints that served the victim certificate, causing TLS disruption or unauthorized substitution.

The record

CVE
CVE-2026-71308
Published
Aug 18, 2026
Updated
Aug 18, 2026
Vendor
Netflix
Product
Lemur
Classifications
CWE-862, CWE-639, T1565.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 18, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 0.5.0, < 1.9.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Netflix · Lemurversion=>= 0.5.0, < 1.9.3

Published CVSS scores

8.1GitHub CNACVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-862Missing Authorization
CWE-639Authorization Bypass Through User-Controlled Key
T1565.001Stored Data Manipulation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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