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TI-2026-49362 Aliases CVE-2026-70667GHSA-f3qq-49m6-rw8f

Time-of-check time-of-use race condition in Netflix lemur

Priority MEDIUM 61CWE-367Published · Updated

Key facts

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

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.

Summary

Lemur manages TLS certificate creation. Prior to 1.9.3, _validate_revocation_url in lemur/certificates/verify.py checked the original CRL or OCSP URL but the later request could reach a different destination. The CRL requests.get call followed HTTP redirects without validating each Location target, so a public attacker-controlled URL could redirect to loopback, RFC1918, link-local, or instance-metadata addresses. Validation and connection also performed separate DNS resolutions, creating a time-of-check time-of-use window for DNS rebinding on both CRL and OCSP paths. An operator uploading a certificate through POST /api/1/certificates/upload could therefore induce blind internal requests despite the earlier mitigation. The fix disables redirects and pins validated addresses while preserving the correct Host value. This issue is fixed in version 1.9.3.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00179 7th 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-f3qq-49m6-rw8f
  • 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-f3qq-49m6-rw8f

Remediation

  • Fix · CNA lemur (Netflix) Fixed in 1.9.3
  • Fix · GHSA-f3qq-49m6-rw8f lemur (PyPI) Fixed in 1.9.3 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-70667
  2. 2026-10-03 Alias added: GHSA-f3qq-49m6-rw8f

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