CVE-2026-18331

HIGHPre-NVD 7.27.2—
EchelonGraph scoreHIGH confidence

Score 7.2 from GitHub Security Advisory (severity: HIGH) published 2026-08-26. a secondary CVSS source baseline 7.2; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
7.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.2Exploit: None knownExposed: 0

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

The Formidable Forms – WordPress Form Builder for Contact Forms, Calculators, Quizzes & More plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'frm_user_id' parameter in all versions up to, and including, 6.33.1 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. By forging frm_user_id to match an administrator's user ID — discoverable via the public WordPress REST API — an unauthenticated attacker causes wp_kses_post() to serve as the only output filter, which preserves the injected payload structurally intact; the plugin's admin JavaScript then decodes and executes it automatically on page load.

CVSS v3
7.2
EG Score
7.2(high)
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
Severity72% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
30%
KEV
Not listed

Published

August 26, 2026

Last Modified

August 26, 2026

References (9)

Vendor Advisories for CVE-2026-18331(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 19× in last 7d / 19× 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. 2026-08-30 01:22 UTCEG score recompute
  2. 2026-08-30 01:22 UTCGHSA enrichment
  3. 2026-08-30 01:22 UTCEPSS rescore
  4. 2026-08-29 13:52 UTCGHSA enrichment
  5. 2026-08-29 02:19 UTCEG score recompute
  6. 2026-08-29 02:19 UTCGHSA enrichment
  7. 2026-08-28 21:41 UTCEPSS rescore
  8. 2026-08-28 14:45 UTCGHSA enrichment
  9. 2026-08-28 03:13 UTCGHSA enrichment
  10. 2026-08-27 15:40 UTCEG score recompute
  11. 2026-08-27 15:40 UTCGHSA enrichment
  12. 2026-08-27 14:25 UTCEPSS rescore
  13. 2026-08-27 04:10 UTCEG score recompute
  14. 2026-08-27 04:10 UTCGHSA enrichment
  15. 2026-08-26 15:54 UTCEG score recompute
  16. 2026-08-26 14:46 UTCEPSS rescore
  17. 2026-08-26 14:23 UTCEG score recompute
  18. 2026-08-26 06:25 UTCEG score recompute
  19. 2026-08-26 06:23 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-18331?
CVE-2026-18331 is a high vulnerability published on August 26, 2026. The Formidable Forms – WordPress Form Builder for Contact Forms, Calculators, Quizzes & More plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'frmuserid' parameter in all versions up to, and including, 6.33.1 due to insufficient input sanitization and output escaping. This…
When was CVE-2026-18331 disclosed?
CVE-2026-18331 was first published in the National Vulnerability Database on August 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-18331 actively exploited?
CVE-2026-18331 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 70.0% of all scored CVEs.
What is the CVSS score of CVE-2026-18331?
CVE-2026-18331 has a CVSS v3 base score of 7.2 (NVD).
How do I remediate CVE-2026-18331?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-18331, 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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