Custom Field Template - Security Vulnerability (CVE-2026-9855)

Q: Am I affected by this vulnerability?

You are affected if your site runs Custom Field Template.

Q: How do I fix it?

Update Custom Field Template to the latest available version. Where the vendor has not yet published a fix, remove or disable the plugin until they do. Until you can update, Request / payload inspection (WAF) in Hack Halt ProSecure contains this class of attack at the request layer.

Q: What can an attacker actually do?

This is a SQL Injection flaw. An attacker who exploits it can read, alter or delete anything in the site database, including user accounts and password hashes.

CVE-2026-9855

Vulnerability CVE-2026-9855 PLUGIN custom-field-template MEDIUM

The Custom Field Template plugin for WordPress is vulnerable to generic SQL Injection via the 'post_ID' parameter in all versions up to, and including, 2.7.8 due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for authenticated attackers, with contributor-level access and above, to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database. The capability check via current_user_can('edit_post', $id) is bypassable because WordPress internally casts $id to an integer for the permission evaluation while the full unsanitized string is preserved and passed to the SQL sink, and a valid nonce — which is also required — can be legitimately obtained by any Contributor-level user from the post edit screen.

CVE-2026-9855

MEDIUM CVSS 6.5 Published 2026-09-19 Updated 2026-09-21

AI Risk Elevated (64/100) Active Exploit: No strong signal Published Exploit: No public exploit references Priority: P3 Priority

Severity Band MEDIUM

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

Affected Components 1

Reference Links 10

AI Risk Engine Elevated (64/100)

Exploitability High

Active Exploitation No strong signal

Published Exploit Status No public exploit references

Threat Timeline

2026-09-19 CVE published and first recorded in the threat feed.
2026-09-21 Record updated with latest vulnerability metadata.
2026-09-23 AI technical context refreshed for mitigation and impact guidance.
Now Monitoring for follow-up changes, linked references, and new related CVEs.

AI Context

Machine-generated threat intelligence

AI Updated 50 days ago

AI enriched 50 days ago (2026-09-23 07:32 UTC)

Technical Summary

Potential Impact

Severity is MEDIUM (CVSS 6.5). Depending on deployment context, affected components may be exposed to unauthorized actions or data integrity risk.

Exploitability Assessment

Exploitability is assessed as High based on remote code execution potential.

Primary risk drivers: remote code execution potential

Mitigation Recommendations

Validate affected product versions, prioritize patching, and monitor references for vendor remediation guidance. If immediate patching is not possible, apply compensating controls and limit exposure of vulnerable surfaces.

Detection & Monitoring

Track authentication anomalies, unexpected file writes, and suspicious plugin API activity around affected components.

Business Impact Lens

AI risk score 64/100 (Elevated, High) with priority P3 Priority. Prioritize remediation where affected components process customer data, admin sessions, or Internet-exposed workflows.

Affected Products

Custom Field Template PLUGIN · custom-field-template Affected: <= 2.7.8 Fixed version not specified

References

What to do about this

Patch promptly The consequence is significant even where an attacker needs a foothold first.

Fix it

Update Custom Field Template to the latest available version.

Where the vendor has not published a fix yet, disable the plugin until they do.

Cannot update today? Request / payload inspection (WAF) in Hack Halt ProSecure blocks this class of attack before WordPress processes the request.

Inspect request parameters and bodies for injection, traversal and file-inclusion payloads, and refuse the request rather than logging it.

Compare Hack Halt plans Start free

Not sure if you are affected?

Scan your site to see whether it runs Custom Field Template, and at which version.

Free, no installation, no account. It reads what your site already publishes, then tells you which plugins carry known vulnerabilities and what to do about each one.

Scan my site free See what Hack Halt does

Am I affected by this vulnerability?