Server-side Request Forgery (SSRF) Affecting lemur package, versions [,1.9.3)
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Start learning- Snyk IDSNYK-PYTHON-LEMUR-19436324
- published31 Aug 2026
- disclosed18 Aug 2026
- creditNguyen Van Hiep
Introduced: 18 Aug 2026
NewCVE-2026-70666 (opens in a new tab)How to fix?
Upgrade lemur to version 1.9.3 or higher.
Overview
lemur is a Certificate management and orchestration service
Affected versions of this package are vulnerable to Server-side Request Forgery (SSRF) via the ACME client following server-controlled URLs in acme_handlers.py. A malicious or compromised ACME server can embed arbitrary internal URLs in its directory, order, authorization, or finalize responses, causing Lemur to issue outbound HTTP requests to those attacker-controlled destinations. Additionally, the acme_url field was not re-validated against ACME_DIRECTORY_HOST_ALLOWLIST on authority update (update) or update_options, allowing an authenticated user with authority-edit privileges to bypass the allowlist and point the ACME client at an arbitrary host.