click5 CRM add-on to WPForms: Unauthenticated stored XSS via post_notifications
Summary
The click5 CRM add-on to WPForms WordPress plugin up to version 1.0.3 does not sanitise or escape content submitted through an unauthenticated endpoint before displaying it on an admin page. An unauthenticated attacker can store a malicious script that runs in the browser of a logged-in administrator who views the affected page. This could allow session theft or actions performed in the name of the administrator.
Affected
- click5 CRM add-on to WPForms (WordPress plugin slug wpf-add-on-by-click5), versions 1.0.3 and earlier
Fixed in
- Unknown. WPScan lists no known fix.
Workaround
- No vendor-issued workaround is known.
- Deactivate and remove the add-on if CRM synchronisation is not business-critical.
- Restrict WordPress admin access (IP allow-listing, two-factor authentication for administrators).
- Review stored form submissions and the affected admin page for unexpected script content.
Exploitation
- CISA KEV: not listed. EPSS: 0.17%.
- CISA SSVC data lists exploitation as none (not verified directly).
- Public proof of concept: unknown.
- No reports of in-the-wild exploitation found.
Our recommendation
- Check whether the click5 CRM add-on is installed on your WordPress sites and treat it as high priority if it is.
- Deactivate and remove the add-on if it is not needed, or restrict admin access until a fixed version is confirmed.
- Monitor the WPScan entry and the vendor for a fix, and update immediately once one is released.
- Review the affected admin page and stored submissions for suspicious script content.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- WPScan vulnerability entry CVE-2026-84259 wpscan.com
- VulDB entry CVE-2026-84259 vuldb.com
- Vulners NVD record CVE-2026-84259 vulners.com
- OpenCVE CVE-2026-84259 app.opencve.io
- GitHub issue tracking CVE-2026-84259 (EPSS) github.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 31 Oct 2026, 20:42.
Original description (NVD)
The click5 CRM add-on to WPForms WordPress plugin through 1.0.3 does not sanitise and escape content submitted through an unauthenticated endpoint before outputting it back in an admin page, leading to Stored XSS which could be used against high privilege users such as admin.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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