CVE-2026-66690Network attack vector

Stored script execution via unescaped donor fields

Published Aug 6, 2026 · Updated Aug 6, 2026

Stored cross-site scripting in Nexcess GiveWP 4.16.5 and earlier allows remote attackers to execute scripts through donor fields. The legacy donation-details template renders attacker-controlled company, email, and phone values into WordPress admin HTML without context-safe escaping. An unauthenticated donation supplies the stored data, but execution requires an administrator or GiveWP staff member to open the affected record.

CVSS severity7.1
High
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Stored cross-site scripting in Nexcess GiveWP 4.16.5 and earlier allows remote attackers to execute scripts through donor fields. The legacy donation-details template renders attacker-controlled company, email, and phone values into WordPress admin HTML without context-safe escaping. An unauthenticated donation supplies the stored data, but execution requires an administrator or GiveWP staff member to open the affected record.

The record

CVE
CVE-2026-66690
Published
Aug 6, 2026
Updated
Aug 6, 2026
Vendor
The Events Calendar
Product
GiveWP
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=n/a <=4.16.5 changes=[{"at":"4.16.5.1","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Events Calendar · GiveWPversion=n/a <=4.16.5 changes=[{"at":"4.16.5.1","status":"unaffected"}]

Published CVSS scores

7.1PatchstackCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007JavaScript/JScript

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo