Unauthenticated stored XSS via forged Stripe webhooks
Published Jul 6, 2026 · Updated Jul 6, 2026
Stored XSS in wp.insider Simple Membership before 4.7.5 allows remote attackers to inject scripts through forged Stripe webhooks. The webhook handler stores an attacker-controlled api_version in swpm_stripe_received_api_old_version, and an administrator notice renders it without escaping. Exploitation requires no configured webhook signing secret, the default after activation, and execution occurs when a logged-in administrator opens an administration page.
Summary
What happened
Stored XSS in wp.insider Simple Membership before 4.7.5 allows remote attackers to inject scripts through forged Stripe webhooks. The webhook handler stores an attacker-controlled api_version in swpm_stripe_received_api_old_version, and an administrator notice renders it without escaping. Exploitation requires no configured webhook signing secret, the default after activation, and execution occurs when a logged-in administrator opens an administration page.
The record
- CVE
- CVE-2026-11855
- Published
- Jul 6, 2026
- Updated
- Jul 6, 2026
- Vendor
- WP Affiliate Manager
- Product
- Simple Membership
- Classifications
- CWE-79, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 6, 2026CVE publishedPublication date reported by the CVE source.
- Jul 6, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <4.7.5
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- WPScan forged Stripe webhook proof of conceptfunctional · validated
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Technologies
Your stack
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Your stack
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