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CVE-2026-70666

CVE-2026-70666 · Lemur: Server-Side Request Forgery via the ACME client following server-controlled URLs

This page contains facts from public vulnerability sources. Check the original advisory before updating.

Lemur manages TLS certificate creation. Prior to 1.9.3, an authority-role member could update acme_url through PUT /api/1/authorities/ without revalidation and direct setup_acme_client_no_retry to an attacker-controlled ACME server. ACME directory and order responses contain newNonce, newOrder, authorizations, and finalize URLs chosen by that server. The Lemur ClientV2 followed those URLs without requiring their host to match the configured directory host, allowing JWS-signed requests to internal services or cloud metadata endpoints. The issue required an ACME authority and a user authorized for that authority, but did not require global administrator privileges. The fix revalidates updates and introduces _PinnedClientNetwork to enforce a single allowed host for the complete ACME flow. This issue is fixed in version 1.9.3.

CVSS 7.4 · High · EPSS 0.2% · Fix available

Published
Updated

Stack: python

Affected products and versions

  • lemur

    Versions
    • < 1.9.3: Affected

    No fix published

  • lemur PyPI

    Versions
    • 0.11.0
    • 0.2.1
    • 0.8.0
    • 0.8.1
    • 0.9.0
    • 1.0.0
    • 1.1.0
    • 1.2.0
    • 1.3.1
    • 1.3.2
    • 1.4.0
    • 1.5.0
    • 1.6.0
    • 1.7.0
    • 1.8.0
    • 1.8.1
    • 1.8.2
    • 1.9.0
    • 1.9.1
    • 1.9.2
    Affected ranges
    • ECOSYSTEM: < 1.9.3

    Update to 1.9.3

Original sources

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