Security readout for executives and security teams
Plain-English summary
CVE-2026-3986 affects the Calculated Fields Form WordPress plugin. A logged-in user with Contributor-level access or higher can save malicious script in form settings. That script can run later when someone views the affected page, creating risk of session theft, unwanted actions, or content tampering within the site context.
Executive priority
Treat as a near-term WordPress hygiene issue, not an emergency based on current evidence. Prioritize sites with contributor access, public registration, or high business value. Remediate during the next maintenance window or sooner if untrusted users can create content.
Technical view
The issue is stored cross-site scripting in Calculated Fields Form through form settings. Sources cite insufficient capability checks on the settings save handler and insufficient sanitization of the fcontent field in fhtml field types. Reported affected versions are all versions up to and including 5.4.5.0. CVSS v3.1 score is 6.4.
Likely exposure
Exposure is limited to WordPress sites using Calculated Fields Form versions up to 5.4.5.0 where untrusted or compromised Contributor-level accounts exist. Sites with public registration, many content contributors, or weak account controls have higher practical risk.
Exploitation context
The attacker needs authenticated Contributor-level or higher access. The provided sources do not show CISA KEV listing or confirmed active exploitation. Successful abuse would store script in plugin form settings and execute it when an affected page is viewed.
Researcher notes
The vulnerability is mapped to CWE-79 and CVSS AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N. The bundle’s affected metadata is sparse, but the description and Wordfence reference state versions up to 5.4.5.0. Patch details are not explicit in the provided sources.
Mitigation direction
- Identify all WordPress sites using Calculated Fields Form.
- Check whether installed versions are 5.4.5.0 or earlier.
- Update to a vendor-confirmed fixed version when available.
- If no fix is available, follow vendor guidance or temporarily disable the plugin.
- Restrict Contributor and higher roles to trusted users only.
- Review and remove unnecessary WordPress accounts with content privileges.
Validation and detection
- Confirm plugin name and version from WordPress administration or asset inventory.
- Verify whether any site remains on version 5.4.5.0 or earlier.
- Review form settings for unexpected custom HTML or script-like content.
- Audit recent changes by Contributor-level and higher accounts.
- Check vendor advisories for fixed-version confirmation and remediation notes.
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-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. 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-2026-3986 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
- 6.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/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:C/C:L/I:L/A:N3.12.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.4MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.wordfence.com/threat-intel/vulnerabilities/id/d650261a-ec0a-4538-ad59-0589712702fa?source=cveCVE reference
- https://plugins.trac.wordpress.org/browser/calculated-fields-form/tags/5.4.4.5/cp_calculatedfieldsf_free.php#L131CVE reference
- https://plugins.trac.wordpress.org/browser/calculated-fields-form/trunk/cp_calculatedfieldsf_free.php#L131CVE reference
- https://plugins.trac.wordpress.org/browser/calculated-fields-form/tags/5.4.4.5/inc/cpcff_form.inc.php#L326CVE reference
- https://plugins.trac.wordpress.org/browser/calculated-fields-form/tags/5.4.4.5/inc/cpcff_page_builders.inc.php#L41CVE 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.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.