CVE-2026-19804

HIGHPre-NVD 8.88.8—
EchelonGraph scoreHIGH confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-09-25. A secondary CVSS source baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
8.8EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1.0%CVSS: 8.8Exploit: 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 s2Member – Excellent for All Kinds of Memberships, Content Restriction Paywalls & Member Access Subscriptions plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 260814 via the 'first_name' parameter parameter. This is due to insufficient sanitization of the first_name parameter via esc_refs(), which strips only regex backreferences and not PHP tags, before substitution into the eval'd Signup Tracking Codes template, combined with disclosure of the site-global proxy verification key that allows PayPal postback verification to be bypassed. This makes it possible for unauthenticated attackers to execute code on the server. Successful exploitation requires that the site administrator has configured a Signup Tracking Codes template containing the %%first_name%% placeholder (a documented, GUI-supported feature) and that the attacker has obtained the site-global proxy verification key, which is exposed in plaintext in the JSON response of any PayPal Checkout AJAX request on the target site.

CVSS v3
8.8
EG Score
8.8HIGHhigh confidence
EG Risk
45
EG Risk 45/100CISA 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
Severity88% × 45%
Exploitation1% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
EPSS PROB
1.0%
EPSS %ILE
62nd
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track or Attend at high (mission-essential systems).

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.

Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). 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 25, 2026

Last Modified

September 25, 2026

References (10)

Vendor Advisories for CVE-2026-19804(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 23× in last 7d / 39× 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 22:54 UTCGHSA enrichment
  3. 2026-10-04 09:41 UTCGHSA enrichment
  4. 2026-10-03 20:24 UTCEG score recompute
  5. 2026-10-03 20:24 UTCGHSA enrichment
  6. 2026-10-03 07:13 UTCGHSA enrichment
  7. 2026-10-02 18:01 UTCEG score recompute
  8. 2026-10-02 18:01 UTCGHSA enrichment
  9. 2026-10-02 04:50 UTCEG score recompute
  10. 2026-10-02 04:50 UTCGHSA enrichment
  11. 2026-10-01 19:49 UTCEPSS rescore
  12. 2026-10-01 15:37 UTCGHSA enrichment
  13. 2026-10-01 02:25 UTCEG score recompute
  14. 2026-10-01 02:25 UTCGHSA enrichment
  15. 2026-09-30 15:03 UTCEPSS rescore
  16. 2026-09-30 13:14 UTCGHSA enrichment
  17. 2026-09-30 00:01 UTCEG score recompute
  18. 2026-09-30 00:01 UTCGHSA enrichment
  19. 2026-09-29 15:20 UTCEPSS rescore
  20. 2026-09-29 10:47 UTCGHSA enrichment
  21. 2026-09-28 21:35 UTCEG score recompute
  22. 2026-09-28 21:35 UTCGHSA enrichment
  23. 2026-09-28 13:51 UTCEPSS rescore
  24. 2026-09-28 08:24 UTCGHSA enrichment
  25. 2026-09-27 19:12 UTCEG score recompute
Show 14 more
  1. 2026-09-27 19:12 UTCGHSA enrichment
  2. 2026-09-27 13:47 UTCEPSS rescore
  3. 2026-09-27 06:00 UTCGHSA enrichment
  4. 2026-09-26 16:48 UTCEG score recompute
  5. 2026-09-26 16:47 UTCGHSA enrichment
  6. 2026-09-26 15:58 UTCEPSS rescore
  7. 2026-09-26 03:36 UTCEG score recompute
  8. 2026-09-26 03:35 UTCGHSA enrichment
  9. 2026-09-25 14:23 UTCGHSA enrichment
  10. 2026-09-25 13:18 UTCEG score recompute
  11. 2026-09-25 13:18 UTCGHSA enrichment
  12. 2026-09-25 08:27 UTCEG score recompute
  13. 2026-09-25 07:47 UTCEG score recompute
  14. 2026-09-25 07:46 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-19804?
CVE-2026-19804 is a high vulnerability published on September 25, 2026. The s2Member – Excellent for All Kinds of Memberships, Content Restriction Paywalls & Member Access Subscriptions plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 260814 via the 'firstname' parameter parameter. This is due to insufficient…
When was CVE-2026-19804 disclosed?
CVE-2026-19804 was first published on September 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-19804 actively exploited?
CVE-2026-19804 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.0% probability of exploitation in the next 30 days (62nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-19804?
CVE-2026-19804 has a CVSS base score of 8.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-19804?
No fix for CVE-2026-19804 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-2026-19804 are linked in the Vendor Advisories panel on this page.

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