CVE-2026-61628

HIGHPre-NVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 65% 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 weekElevated
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.1Exploit: Elevated riskExposed: 0

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

nginx ignition is a user interface for the nginx web server. Prior to version 2.41.1, POST /api/users/onboarding/finish is registered as anonymous (unauthenticated) and creates a user with full ReadWrite admin permissions. Because the handler uses a check-then-act (TOCTOU) pattern between the "onboarding already completed?" check and the user-creation write, with no atomic guard, a remote unauthenticated attacker who can reach an instance in its pre-onboarding state can create an administrator account for themselves — and concurrent requests can create multiple admin accounts in a single race. Version 2.41.1 patches the issue.

CVSS v3
8.1
EG Score
8.1(medium)
EG Risk
52(Track*)
EG Risk 52/100SSVC: 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
Severity81% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Watch closely — could escalate to Attend.
EPSS PROB
0%
EPSS %ILE
35%
KEV
Not listed

Published

September 21, 2026

Last Modified

September 23, 2026

Advisory Details (2)

Auto-updated Sep 21, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit.
github_commit

commit 0586b4e55ab7 (lucasdillmann/nginx-ignition)

Fix landed in lucasdillmann/nginx-ignition commit 0586b4e55ab7 — awaiting tagged release

https://github.com/lucasdillmann/nginx-ignition/commit/0586b4e55ab780676d3553a2592979dfa2fb0183
github Patch Available🟡 PoC Available

Unauthenticated Admin Account Creation via Onboarding Race Condition · Advisory · lucasdillmann/nginx-ignition · GitHub

https://github.com/lucasdillmann/nginx-ignition/security/advisories/GHSA-pxcx-fv34-x9p5

Vendor Advisories for CVE-2026-61628(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)
Go(1)
PackageVulnerable rangeFixed inDependents
github.com/lucasdillmann/nginx-ignition—0.0.0-20260621194639-0586b4e55ab—

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. 2026-09-24 17:11 UTCEG score recompute
  2. 2026-09-23 18:39 UTCEG score recompute
  3. 2026-09-23 17:54 UTCEPSS rescore
  4. 2026-09-23 01:12 UTCEG score recompute
  5. 2026-09-21 15:22 UTCEG score recompute
  6. 2026-09-21 15:15 UTCEG score recompute
  7. 2026-09-21 14:50 UTCEG score recompute
  8. 2026-09-21 14:50 UTCMITRE cvelistV5first tracked

Related CVEs(same product + same CWE)

Same product

2 shown

Go:github.com/lucasdillmann/nginx-ignition

Frequently asked(5)

What is CVE-2026-61628?
CVE-2026-61628 is a high vulnerability published on September 21, 2026. nginx ignition is a user interface for the nginx web server. Prior to version 2.41.1, POST /api/users/onboarding/finish is registered as anonymous (unauthenticated) and creates a user with full ReadWrite admin permissions. Because the handler uses a check-then-act (TOCTOU) pattern between the…
When was CVE-2026-61628 disclosed?
CVE-2026-61628 was first published in the National Vulnerability Database on September 21, 2026, with the most recent update on September 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-61628 actively exploited?
CVE-2026-61628 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 65.0% of all scored CVEs.
What is the CVSS score of CVE-2026-61628?
CVE-2026-61628 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2026-61628?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-61628, 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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