{"id":"CVE-2026-71303","summary":"Lemur: Incomplete fix for CVE-2026-55166 -- ACME authority update endpoint allows non-admin to replace `acme_url` with internal IP, bypassing allowlist","details":"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.","aliases":["GHSA-v5rc-cpwc-cfpr","PYSEC-2026-3679"],"modified":"2026-08-20T03:55:02.615182603Z","published":"2026-08-18T19:03:55.524Z","database_specific":{"cwe_ids":["CWE-918"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/71xxx/CVE-2026-71303.json","cna_assigner":"GitHub_M"},"references":[{"type":"WEB","url":"https://github.com/Netflix/lemur/releases/tag/v1.9.3"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/71xxx/CVE-2026-71303.json"},{"type":"ADVISORY","url":"https://github.com/Netflix/lemur/security/advisories/GHSA-v5rc-cpwc-cfpr"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-71303"},{"type":"FIX","url":"https://github.com/Netflix/lemur/commit/edca0390f930344d65ff4ca37a669c2320e3dfad"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/netflix/lemur","events":[{"introduced":"0"},{"fixed":"edca0390f930344d65ff4ca37a669c2320e3dfad"},{"fixed":"726506d15a6da8d9bcf5c39b4dc0c95535cf03c0"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"1.9.3"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["v1.9.2","v1.9.1","v1.9.0","v1.8.2","v1.8.1","v1.8.0","v1.7.0","v1.6.0","v1.5.0","v1.4.0","v1.3.2","v1.3.1","v1.3.0","v1.2.0","v1.1.0","v1.0.0","v0.11.0","v0.10.0","v0.9.0","v0.8.1","0.8.0","0.7.0","0.6.0","0.5.0","0.4.0","0.3.0","0.2.2","0.2.1","0.2","0.1.5","0.1.4","0.1.3","0.1.2","0.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-71303.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N"}]}