CVE-2026-16557

MEDIUMPre-NVD 4.34.3—
EchelonGraph scoreHIGH confidence

Score 4.3 from GitHub Security Advisory published 2026-09-19. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 4.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this week
4.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 4.3Exploit: None knownExposed services: Not assessed

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

The Nimble Page Builder WordPress plugin through 3.3.8 does not perform an authorization check when returning page-builder content through an authenticated AJAX action, allowing any authenticated user (Subscriber+) to disclose the page-builder content of arbitrary non-public (draft, pending, private, scheduled) posts and pages.

CVSS v3
4.3
EG Score
4.3MEDIUMhigh confidence
EG Risk
19
EG Risk 19/100CISA SSVC

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
Severity43% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.
EPSS PROB
0.2%
EPSS %ILE
6th
KEV
Not listed

CISA SSVCTrack at every mission impact level.

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 19, 2026

Last Modified

September 21, 2026

Advisory Details (1)

Auto-updated Sep 19, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic🟡 PoC Available

Nimble Builder <= 3.3.8 – Subscriber+ Non-Public Content Disclosure via sek_get_nimble_content_for_seo_plugins | CVE 2026-16557 | Plugin Vulnerabilities

https://wpscan.com/vulnerability/a47221d4-bd82-4813-a2de-423fbe014ea0/

Vendor Advisories for CVE-2026-16557(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 17× in last 7d / 41× 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. 2026-10-04 23:21 UTCEPSS rescore
  2. 2026-10-04 19:21 UTCGHSA enrichment
  3. 2026-10-03 16:59 UTCEG score recompute
  4. 2026-10-03 16:59 UTCGHSA enrichment
  5. 2026-10-03 14:25 UTCEPSS rescore
  6. 2026-10-02 14:37 UTCEG score recompute
  7. 2026-10-02 14:37 UTCGHSA enrichment
  8. 2026-10-01 19:49 UTCEPSS rescore
  9. 2026-10-01 11:58 UTCEG score recompute
  10. 2026-10-01 11:58 UTCGHSA enrichment
  11. 2026-09-30 15:02 UTCEPSS rescore
  12. 2026-09-30 09:34 UTCEG score recompute
  13. 2026-09-30 09:34 UTCGHSA enrichment
  14. 2026-09-29 15:20 UTCEPSS rescore
  15. 2026-09-29 06:59 UTCEG score recompute
  16. 2026-09-29 06:59 UTCGHSA enrichment
  17. 2026-09-28 13:51 UTCEPSS rescore
  18. 2026-09-28 04:37 UTCEG score recompute
  19. 2026-09-28 04:37 UTCGHSA enrichment
  20. 2026-09-27 13:47 UTCEPSS rescore
  21. 2026-09-27 02:14 UTCEG score recompute
  22. 2026-09-27 02:14 UTCGHSA enrichment
  23. 2026-09-26 15:58 UTCEPSS rescore
  24. 2026-09-25 23:52 UTCGHSA enrichment
  25. 2026-09-24 21:30 UTCEG score recompute
Show 16 more
  1. 2026-09-24 21:30 UTCGHSA enrichment
  2. 2026-09-23 19:09 UTCEG score recompute
  3. 2026-09-23 19:08 UTCGHSA enrichment
  4. 2026-09-22 16:06 UTCEG score recompute
  5. 2026-09-22 16:06 UTCGHSA enrichment
  6. 2026-09-21 13:43 UTCEG score recompute
  7. 2026-09-21 13:43 UTCGHSA enrichment
  8. 2026-09-20 16:49 UTCEG score recompute
  9. 2026-09-20 16:49 UTCGHSA enrichment
  10. 2026-09-19 14:27 UTCGHSA enrichment
  11. 2026-09-19 13:25 UTCEG score recompute▲ 4.30
  12. 2026-09-19 13:25 UTCGHSA enrichment
  13. 2026-09-19 13:24 UTCMITRE cvelistV5CVSS v3 → 4.3 · severity → MEDIUM
  14. 2026-09-19 07:17 UTCNVD update
  15. 2026-09-19 06:26 UTCEG score recompute
  16. 2026-09-19 06:25 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-16557?
CVE-2026-16557 is a medium vulnerability published on September 19, 2026. The Nimble Page Builder WordPress plugin through 3.3.8 does not perform an authorization check when returning page-builder content through an authenticated AJAX action, allowing any authenticated user (Subscriber+) to disclose the page-builder content of arbitrary non-public (draft, pending,…
When was CVE-2026-16557 disclosed?
CVE-2026-16557 was first published on September 19, 2026, with the most recent update on September 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-16557 actively exploited?
CVE-2026-16557 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (6th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-16557?
CVE-2026-16557 has a CVSS v3.1 base score of 4.3 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-16557?
No fix for CVE-2026-16557 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-16557 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-16557

Explore →

Is Your Infrastructure Affected by CVE-2026-16557?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs