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TI-2026-49964 Aliases CVE-2026-71303GHSA-v5rc-cpwc-cfpr

Server-side request forgery in Netflix lemur

Priority HIGH 67CWE-918Published · Updated

Key facts

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

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-918 and the CVSS impact.

Summary

Lemur manages TLS certificate creation. Prior to 1.9.3, _validate_acme_url enforced ACME_DIRECTORY_HOST_ALLOWLIST when an authority was created, but PUT /api/1/authorities/ passed options to lemur/authorities/service.py without applying the same check. A user holding an authority role could replace the stored acme_url with an internal service or instance-metadata URL such as 169.254.169.254. The next issuance operation loaded that value and passed it to ClientV2.get_directory, causing an outbound request from the Lemur backend. This bypassed the creation-time mitigation for CVE-2026-55166 and could expose internal services or cloud metadata. The fix revalidates acme_url whenever authority options are updated. This issue is fixed in version 1.9.3.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00277 20th 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
Netflixlemurbefore 1.9.31.9.3Patch availableCNA
—lemur (PyPI)before 1.9.31.9.3Patch availableGHSA-v5rc-cpwc-cfpr
  • lemur VendorNetflix Affected before 1.9.3 Fixed in 1.9.3 Patch available CNA
  • lemur (PyPI) Vendor— Affected before 1.9.3 Fixed in 1.9.3 Patch available GHSA-v5rc-cpwc-cfpr

Remediation

  • Fix · CNA lemur (Netflix) Fixed in 1.9.3
  • Fix · GHSA-v5rc-cpwc-cfpr lemur (PyPI) Fixed in 1.9.3 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-71303
  2. 2026-10-03 Alias added: GHSA-v5rc-cpwc-cfpr

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-2026-49966 Lemur: Unchecked `replaces[]` lets any user silence notifications and hijack auto-rotation for arbitrary certificates CVSS 3.1HIGH 8.1
  • TI-2026-49965 Missing authorization 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