CVE-2026-6399
MediumWhat is CVE-2026-6399?
The General Options plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to and including 1.1.0. This is due to the use of sanitize_text_field() for output escaping in the Contact Number (ad_contact_number) field — a function that strips HTML tags but does not encode double-quote characters to their HTML entity equivalent ("). When the stored value is echoed inside a double-quoted HTML attribute (value="..."), an attacker-supplied double-quote character breaks out of the attribute context. Even with WordPress's wp_magic_quotes mechanism (which prefixes quotes with a backslash), the resulting \" sequence is NOT treated as an escaped quote by HTML parsers — the backslash is rendered as a literal character and the bare double-quote still closes the attribute. This makes it possible for authenticated attackers with Administrator-level access and above to inject arbitrary web scripts in the admin settings page that will execute whenever any administrator visits the General Options settings page.
CVSS Vector Breakdown
CVSS 3.1Exploitable remotely over the network without requiring access to the local system.
Exploit requires specific conditions, timing, or configuration to succeed.
Administrative or root-level privileges required to exploit.
No user interaction required. Exploit runs without any victim action.
Exploiting the vulnerability can affect other components beyond the vulnerable one.
Some sensitive information is disclosed, but attacker has limited access.
Attacker can modify some data, but scope or consequence is limited.
No availability impact. Service remains fully operational.
FAQ
CVE-2026-6399 has a CVSS score of 4.4/10, rated as Medium. Review the affected products list and apply vendor patches.
CVSS (Common Vulnerability Scoring System) rates vulnerability severity from 0.0 to 10.0. CVE-2026-6399 scores 4.4/10 (Medium). Scores 9.0–10.0 are Critical, 7.0–8.9 are High, 4.0–6.9 are Medium, and below 4.0 are Low.
The list of devices confirmed to be affected by CVE-2026-6399 is shown in the "Affected Devices" section above. Check your firmware version against the vendor security advisory and apply the latest patch.
Apply the latest firmware or software update from the vendor. Check the References section above for official advisories and patch notes. If no patch is available, consider disabling the affected feature or isolating the device from untrusted networks.