JSON API User <= 4.1.0 - Authenticated (Subscriber+) Stored Cross-Site Scripting via 'content' Parameter
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-79.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-9626
- 2026-10-03 Alias added: GHSA-4689-rgvq-62r3
References
Other 6
- https://www.wordfence.com/threat-intel/vulnerabilities/id/c41b0370-2881-4053-98b1-9c70251a3b63?source=cve
- https://plugins.trac.wordpress.org/browser/json-api-user/tags/4.1.0/controllers/User.php#L1007
- https://plugins.trac.wordpress.org/browser/json-api-user/tags/4.1.0/controllers/User.php#L995
- https://plugins.trac.wordpress.org/browser/json-api-user/tags/4.1.0/controllers/User.php#L979
- https://plugins.trac.wordpress.org/changeset/3576431/json-api-user/trunk/controllers/User.php
- https://plugins.trac.wordpress.org/changeset?old_path=%2Fjson-api-user/tags/4.1.0&new_path=%2Fjson-api-user/tags/4.1.2
More parorrey vulnerabilities
- TI-2024-06142 JSON API User <= 3.9.3 - Unauthenticated Privilege Escalation CVSS 3.1CRITICAL 9.8
- TI-2026-65998 JSON API Auth <= 3.1.2 - Unauthenticated Authentication Bypass via Cached 'generate_auth_cookie' Response CVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-9626 · CVE Program
- CVE-2026-9626 · NVD
- FIRST EPSS
- GHSA-4689-rgvq-62r3 · GitHub Advisory Database · CC BY 4.0
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