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Cross-site Scripting (XSS)Weakness · CWE-79

CVE-2026-9626

MEDIUM · 6.4 CVSS v3.1 Published 2026-07-03
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
70/100
Remediation priority · Elevated
Remotely reachable Zero-click 7 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The JSON API User plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'content' parameter of the post_comment API endpoint in versions up to, and including, 4.1.0 This is due to insufficient input sanitization in the post_comment() function, which passes the attacker-controlled comment_content value directly to wp_insert_comment() without applying any HTML sanitization, and additionally allows the caller to set comment_approved=1 to self-approve the comment and bypass moderation. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

The JSON API User WordPress plugin has a stored XSS vulnerability in the post_comment API endpoint. The post_comment() function fails to sanitize the 'content' parameter before passing it to wp_insert_comment(), and allows setting comment_approved=1 to bypass moderation, enabling authenticated attackers with subscriber-level access to inject malicious scripts that execute when users view the injected comments.

MitigationUpdate to a patched version of the JSON API User plugin that properly sanitizes comment content and prevents caller-controlled comment approval, or implement WAF rules to block malicious comment submissions.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify if JSON API User plugin is installed
    In WordPress admin, go to Plugins > Installed Plugins and look for 'JSON API User' or check the plugin files in wp-content/plugins/ for the json-api-user directory. Read the main plugin file header for the version number.
    Affected if The plugin is installed and the version lacks the security fix for sanitizing comment content.
  2. Confirm the post_comment API endpoint is enabled
    Make a GET request to /?json=controller.get_methods or check the plugin settings page in WordPress admin under Settings > JSON API to verify the 'post_comment' method is listed as active.
    Affected if The post_comment endpoint is enabled and accessible via the API.
  3. Verify subscriber-level accounts can access the API
    Check WordPress user roles at Users > All Users and confirm that the 'subscriber' role exists. Test API access using valid subscriber credentials by making a request to /?json=post_comment with a subscriber-level API key or auth token.
    Affected if Subscriber-level users can successfully authenticate to the API and call the post_comment endpoint.
  4. Inspect comments table for unapproved or suspicious entries
    In WordPress admin go to Comments, or query the wp_comments database table directly. Look for comments with comment_approved=1 that contain script tags, javascript:, onload, onerror, or other XSS vectors in the comment_content field.
    Affected if There are comments in the database with comment_approved=1 containing potentially malicious script content that was injected via the API.

Your environment is affected if the JSON API User plugin is installed with the vulnerable endpoint enabled, subscriber-level users have API access, and any comments exist in the database that bypassed moderation (comment_approved=1) and contain script injection patterns.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update to a patched version of the JSON API User plugin that properly sanitizes comment content and prevents caller-controlled comment approval, or implement WAF rules to block malicious comment submissions.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-9626 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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