CVE-2026-66565
Unauthenticated PHP Object Injection in FC United WordPress theme <=1.1.1
Is CVE-2026-66565 being exploited?
Not confirmed. CVE-2026-66565 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 0.31% probability of exploitation in the next 30 days.
How severe is CVE-2026-66565?
CVE-2026-66565 is rated Critical with a CVSS score of 9.8. 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-2026-66565?
Not known from our data. No patch reference has been recorded for CVE-2026-66565, which is not the same as no patch existing — a fix may have shipped without a tagged reference, or after this record was written. The vendor advisory is the only authority on whether a fix exists, and mitigations may be available regardless.
What does CVE-2026-66565 affect?
CVE-2026-66565 affects FC United WordPress theme <= 1.1.1, WordPress sites using the FC United theme. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-66565?
Disable/remove the theme or isolate affected sites; apply vendor patch immediately when released.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated PHP object injection enabling remote code execution, full site takeover, file access, and data exposure.
Immediate action required
- affected<= 1.1.1
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.