CVE-2026-19513
HIGHCVE-2026-19513 is a high-severity (CVSS 8.1) Unrestricted File Upload vulnerability. O3 Security confirms whether CVE-2026-19513 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
The Gravity Forms plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 3.0.2. This is due to insufficient validation of multi-file upload…
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-19513.
Description
The Gravity Forms plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 3.0.2. This is due to insufficient validation of multi-file upload chunk state in the GFAsyncUpload::upload() function, where public form state URL hashes can be reused as chunk continuation hashes and attacker-controlled temporary filenames are accepted before sanitization. This makes it possible for unauthenticated attackers, when a public form contains a File Upload field with Multiple Files enabled, to upload a valid PNG/PDF polyglot to an attacker-selected public .php or .html filename in the Gravity Forms temporary upload directory. This can lead to remote code execution on WordPress systems that use NGINX or other non .htaccess respecting web servers. NOTE: During installation and activation, the Gravity Forms plugin places a .htaccess file in this directory, which prevents this vulnerability from being exploited despite the PHP file being written to the temporary upload directory. In these cases where PHP execution is blocked, attacker-written HTML can result in stored same-origin cross-site scripting if a victim visits the generated file URL.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-19513 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-19513 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-19513. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-19513 in your dependencies?
O3 detects CVE-2026-19513 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.