Security readout for executives and security teams
Plain-English summary
CVE-2026-4066 affects the Smart Custom Fields WordPress plugin up to version 5.0.6. A logged-in user with Contributor-level access or higher may read private or draft post content from other authors. This is a confidentiality issue, not a site takeover issue based on the provided sources.
Executive priority
Treat this as a moderate-priority privacy and content governance issue. Prioritize sites with many contributors, external writers, embargoed content, or sensitive drafts. It does not indicate remote unauthenticated compromise, but it can expose unpublished or private business information.
Technical view
The plugin’s relational_posts_search() AJAX handler checks only the generic edit_posts capability. It queries posts with post_status=any and returns full WP_Post objects, including post_content, without verifying per-post read permissions. The issue is mapped to CWE-862 and has CVSS 3.1 score 4.3.
Likely exposure
Exposure is limited to WordPress sites running Smart Custom Fields 5.0.6 or older where Contributor-level or higher accounts exist, especially untrusted contributors. Anonymous users are not described as affected. Sites without the plugin, without affected versions, or without such authenticated users have lower practical exposure.
Exploitation context
The provided sources do not show active exploitation, and the CVE is not marked KEV. Exploitation requires valid WordPress credentials with Contributor-level or higher permissions. The likely impact is disclosure of private or draft post content belonging to other authors.
Researcher notes
Key evidence is the missing authorization check in relational_posts_search(), use of post_status=any, and return of full WP_Post objects. The referenced Trac changeset appears relevant, but the provided bundle does not clearly name a fixed release. Avoid assuming exploit activity or patch status beyond cited sources.
Mitigation direction
- Identify all WordPress sites using Smart Custom Fields.
- Update Smart Custom Fields beyond version 5.0.6 if an official release is available.
- If no update is available, follow vendor or WordPress plugin guidance.
- Restrict Contributor and higher roles to trusted users only.
- Remove unnecessary authoring accounts and review role assignments.
Validation and detection
- Confirm whether Smart Custom Fields is installed.
- Check whether the installed version is 5.0.6 or older.
- Review sites for untrusted Contributor, Author, Editor, or Administrator accounts.
- Verify vendor changelog or WordPress Trac changeset for authorization fixes.
- Test remediation in staging before production deployment.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-862: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-4066 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 4.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N2.81.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.wordfence.com/threat-intel/vulnerabilities/id/87f52e3a-e414-4f47-b46c-e3811e76744b?source=cveCVE reference
- https://plugins.trac.wordpress.org/browser/smart-custom-fields/trunk/classes/fields/class.field-related-posts.php#L101CVE reference
- https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&new=3485210%40smart-custom-fields%2Ftrunk&old=3416964%40smart-custom-fields%2Ftrunk&sfp_email=&sfph_mail=#file2CVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Missing Authorization
Missing Authorization represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.