CVE-2026-70666

HIGHPre-NVD 7.47.4—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.4 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 94% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 3 sources updated this week
7.4EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.4Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
7.4
EG Score
7.4(medium)
EG Risk
33(Track)
EG Risk 33/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity74% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
6%
KEV
Not listed

Published

August 18, 2026

Last Modified

August 19, 2026

Advisory Details (3)

Auto-updated Aug 18, 2026
🔬 Proof of concept available. Patch available. Sources: github_release, github, github_commit.
github_release Patch Available

v1.9.3

Patch available: Netflix/lemur v1.9.3

https://github.com/Netflix/lemur/releases/tag/v1.9.3
github_commit Patch Available

commit 6dcb19b6d600 (Netflix/lemur)

Patch available: Netflix/lemur v1.9.3 (contains commit 6dcb19b6d600)

https://github.com/Netflix/lemur/commit/6dcb19b6d6004e97796d6a0344b130b2ba57f050
github Patch Available🟡 PoC Available

Server-Side Request Forgery via the ACME client following server-controlled URLs · Advisory · Netflix/lemur · GitHub

https://github.com/Netflix/lemur/security/advisories/GHSA-xpmj-wjcp-6pww

Vendor Advisories for CVE-2026-70666(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
lemur0.11.0 ... 1.9.2 (20 versions)1.9.3—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 8× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-21 08:12 UTCEG score recompute
  2. 2026-08-20 22:56 UTCEPSS rescore
  3. 2026-08-19 19:21 UTCEG score recompute
  4. 2026-08-19 18:38 UTCEG score recompute
  5. 2026-08-19 17:04 UTCEPSS rescore
  6. 2026-08-18 20:22 UTCEG score recompute
  7. 2026-08-18 19:19 UTCEG score recompute
  8. 2026-08-18 19:18 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-70666?
CVE-2026-70666 is a high vulnerability published on August 18, 2026. Lemur manages TLS certificate creation. Prior to 1.9.3, an authority-role member could update acmeurl through PUT /api/1/authorities/ without revalidation and direct setupacmeclientnoretry to an attacker-controlled ACME server. ACME directory and order responses contain newNonce, newOrder,…
When was CVE-2026-70666 disclosed?
CVE-2026-70666 was first published in the National Vulnerability Database on August 18, 2026, with the most recent update on August 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-70666 actively exploited?
CVE-2026-70666 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 93.8% of all scored CVEs.
What is the CVSS score of CVE-2026-70666?
CVE-2026-70666 has a CVSS v3 base score of 7.4 (NVD).
How do I remediate CVE-2026-70666?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-70666, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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