The Simple Membership WordPress plugin before 4.7.5 does not verify the authenticity of Stripe webhook requests when no signing secret is configured, nor escape a value taken from them before outputting it in an administrator notice, allowing unauthenticated attackers to inject arbitrary web scripts that execute in the context of a logged-in administrator.
CVE-2026-11855
HIGHPre-NVD 8.8Trending — 4 sources updated this weekElevated
8.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 8.8Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 8.8
- EG Score
- 0.0(none)
- EPSS
- 7.8%
- KEV
- Not listed
Published
July 6, 2026
Last Modified
July 6, 2026
Advisory Details (1)
Auto-updated Jul 6, 2026🔬 Proof of concept available. No patch confirmed yet.
generic🟡 PoC Available
Simple Membership < 4.7.5 – Unauthenticated Stored XSS via Stripe Webhook API Version | CVE 2026-11855 | Plugin Vulnerabilities
https://wpscan.com/vulnerability/217cb606-a0f2-4427-9262-cfe1cc90474e/Vendor Advisories for CVE-2026-11855(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Data Freshness Timeline
(refreshed 5× in last 7d / 5× 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.
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 13:07 UTCMITRE cvelistV5CVSS v3 → 8.8 · severity → HIGH
- 2026-07-06 09:42 UTCNVD update
- 2026-07-06 07:23 UTCEG score recompute
- 2026-07-06 07:22 UTCMITRE cvelistV5first tracked
Frequently asked(5)
What is CVE-2026-11855?
CVE-2026-11855 is a high vulnerability published on July 6, 2026. The Simple Membership WordPress plugin before 4.7.5 does not verify the authenticity of Stripe webhook requests when no signing secret is configured, nor escape a value taken from them before outputting it in an administrator notice, allowing unauthenticated attackers to inject arbitrary web…
When was CVE-2026-11855 disclosed?
CVE-2026-11855 was first published in the National Vulnerability Database on July 6, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-11855 actively exploited?
CVE-2026-11855 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 7.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-11855?
CVE-2026-11855 has a CVSS v3.1 base score of 8.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 0.0.
How do I remediate CVE-2026-11855?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-11855, 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
Explore the affected products and dependency analysis for CVE-2026-11855
Is Your Infrastructure Affected by CVE-2026-11855?
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