Unauthenticated arbitrary file write in a widely deployed WordPress plugin can lead to mass site takeovers and will attract broad attention.
CVE-2026-18051
Unauthenticated arbitrary file-write in W3 Total Cache allows site takeover.
Is CVE-2026-18051 being exploited?
Not confirmed. CVE-2026-18051 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 0.44% probability of exploitation in the next 30 days.
How severe is CVE-2026-18051?
CVE-2026-18051 is rated Critical with a CVSS score of 10.0. 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-2026-18051?
Yes. A fix has been recorded for CVE-2026-18051. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-18051 affect?
CVE-2026-18051 affects WordPress plugin W3 Total Cache < 2.10.5, Apache-hosted WordPress sites, Any server with writable existing directories used by the plugin. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-18051?
Upgrade W3 Total Cache to >=2.10.5, verify/restore .htaccess and critical files, audit logs
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated HTTP file-write to arbitrary existing directories; can overwrite .htaccess or webroot files enabling remote code execution, persistence, and site takeover.
Immediate action required
- affected< 2.10.5
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.