CVE-2026-11855
Unauthenticated Stripe webhook can inject scripts in admin notices.
Is CVE-2026-11855 being exploited?
Not confirmed. CVE-2026-11855 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.51% probability of exploitation in the next 30 days.
How severe is CVE-2026-11855?
CVE-2026-11855 is rated High with a CVSS score of 8.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-11855?
Yes. A fix has been recorded for CVE-2026-11855. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-11855 affect?
CVE-2026-11855 affects WordPress, Simple Membership plugin <= 4.7.4. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-11855?
Patch to 4.7.5; enable Stripe webhook signing secret.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
XSS in WordPress admin: unauthenticated webhook content executes as admin, risking session hijack.
Immediate action required
- affected< 4.7.5
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.