Unauthenticated PHP object injection enabling RCE in a widely used WordPress plugin (Gravity Forms) that can enable mass site takeovers; high-impact for many web properties.
CVE-2026-103039
Unauthenticated PHP object injection in Gravity Forms can lead to remote code execution and site takeover.
Is CVE-2026-103039 being exploited?
Not confirmed. CVE-2026-103039 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.
How severe is CVE-2026-103039?
CVE-2026-103039 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-2026-103039?
Not known from our data. No patch reference has been recorded for CVE-2026-103039, 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-2026-103039 affect?
CVE-2026-103039 affects Gravity Forms WordPress plugin <= 3.1.2, WordPress sites using Post Custom Field 'List' type, Themes/plugins providing PHP object gadget chains, Hosts with readable PEAR + register_argc_argv (RCE path). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-103039?
Disable/remove vulnerable fields or plugin, deploy WAF rules, inventory sites, apply vendor patch when released.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated PHP Object Injection allowing remote code execution and full site takeover via crafted Post Custom Field input and gadget chains (or WP page template path).
Immediate action required
- affected<= 3.1.2
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.