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TI-2026-49966 Aliases CVE-2026-71308GHSA-cfh6-pv5c-38jv

Lemur: Unchecked `replaces[]` lets any user silence notifications and hijack auto-rotation for arbitrary certificates

Priority HIGH 68CWE-639Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
None · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-639.

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 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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00317 24th percentileScored 2026-11-07
Fix Fixed lemur (Netflix): 1.9.3lemur (PyPI): 1.9.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Netflixlemur0.5.0 to before 1.9.31.9.3Patch availableCNA
—lemur (PyPI)0.5.0 to before 1.9.31.9.3Patch availableGHSA-cfh6-pv5c-38jv
  • lemur VendorNetflix Affected 0.5.0 to before 1.9.3 Fixed in 1.9.3 Patch available CNA
  • lemur (PyPI) Vendor— Affected 0.5.0 to before 1.9.3 Fixed in 1.9.3 Patch available GHSA-cfh6-pv5c-38jv

Remediation

  • Fix · CNA lemur (Netflix) Fixed in 1.9.3
  • Fix · GHSA-cfh6-pv5c-38jv lemur (PyPI) Fixed in 1.9.3 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-71308
  2. 2026-10-03 Alias added: GHSA-cfh6-pv5c-38jv

References

Other 4

  • TI-2024-04374 Path Traversal vulnerability via File Uploads in Genie CVSS 3.1CRITICAL 9.9
  • TI-2023-21044 Dispatch writes JWT tokens in error message CVSS 3.1CRITICAL 9.1
  • TI-2026-39854 Improper authorization in Netflix lemur CVSS 3.1CRITICAL 9.9
  • TI-2026-32272 Lemur: LDAP Filter Injection enables post-authentication privilege escalation CVSS 3.1HIGH 8.1
  • TI-2026-49965 Missing authorization in Netflix lemur CVSS 3.1HIGH 7.7
  • TI-2026-49964 Server-side request forgery in Netflix lemur CVSS 3.1HIGH 7.7
See all 33 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences