Vulnerability Description
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.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://github.com/Netflix/lemur/commit/ed504a830f38a83825b1570302e9f38d6553938a
- https://github.com/Netflix/lemur/releases/tag/v1.9.3
- https://github.com/Netflix/lemur/security/advisories/GHSA-f3qq-49m6-rw8f
- https://github.com/Netflix/lemur/security/advisories/GHSA-54vg-pfh7-jq95
FAQ
What is CVE-2026-70667?
CVE-2026-70667 is a vulnerability with a CVSS score of 6.3 (MEDIUM). 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 dest...
How severe is CVE-2026-70667?
CVE-2026-70667 has been rated MEDIUM with a CVSS base score of 6.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-70667?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.