{"cve":"CVE-2026-55166","nvd":{"published":"2026-08-18T19:16:58.783","modified":"2026-09-08T21:02:26.047","status":"Deferred","description":"Lemur manages TLS certificate creation. Prior to 1.9.2, authenticated users could influence an ACME authority acme_url without an effective server-side destination restriction and trigger AcmeHandler.setup_acme_client to make backend requests. An attacker could target cloud instance metadata or internal services from Lemur network context, potentially obtaining credentials available to the host. The advisory also identifies creator-equality authorization behavior that could preserve access to certificate key material after ownership or role changes, with insufficient export_private_key audit context to distinguish that access path. Together, the acme_url server-side request forgery and authorization weakness could expose cloud credentials and long-lived PKI private-key access. The fix adds ACME_DIRECTORY_HOST_ALLOWLIST validation and enriches key-export audit events with creator and current-owner context. This issue is fixed in version 1.9.2.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L","score":9.9},"cwes":["CWE-285","CWE-639","CWE-918"],"references":["https://github.com/Netflix/lemur/commit/872f6e282542352f2bf3f6e2bcc504ab81e1843d","https://github.com/Netflix/lemur/releases/tag/v1.9.2","https://github.com/Netflix/lemur/security/advisories/GHSA-v2wp-frmc-5q3v","https://github.com/Netflix/lemur/security/advisories/GHSA-v2wp-frmc-5q3v"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:49:10.689564601+00:00"},"epss":{"cve":"CVE-2026-55166","score":0.00287,"percentile":0.21227,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-v2wp-frmc-5q3v","url":"https://osv.dev/vulnerability/GHSA-v2wp-frmc-5q3v","summary":"Lemur: ACME SSRF + creator-equality IDOR lead to AWS IAM/PKI compromise","modified":"2026-06-29T12:26:09.552045810Z","packages":[{"ecosystem":"PyPI","name":"lemur","purl":"pkg:pypi/lemur","ranges":["<1.9.2"],"fixed":["1.9.2"]}]},{"id":"PYSEC-2026-384","url":"https://osv.dev/vulnerability/PYSEC-2026-384","summary":"Lemur: ACME SSRF + creator-equality IDOR lead to AWS IAM/PKI compromise","modified":"2026-07-01T21:45:31.174888055Z","packages":[{"ecosystem":"PyPI","name":"lemur","purl":"pkg:pypi/lemur","ranges":["<1.9.2"],"fixed":["1.9.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}