Security readout for executives and security teams
Plain-English summary
Forminator versions through 1.57.0 are reported vulnerable to an unauthenticated PHP object injection flaw. A remote attacker may be able to compromise confidentiality, integrity, and availability without credentials or user interaction. The supplied sources do not establish the exact attack path, exploitation prerequisites beyond network access, or a fixed version.
Executive priority
Treat as an immediate critical-priority investigation for internet-facing WordPress environments. Rapidly establish whether Forminator 1.57.0 or earlier is active, then follow confirmed vendor guidance. The lack of cited active exploitation evidence reduces certainty about current attacks, but the unauthenticated network vector and potential high business impact justify urgent action.
Technical view
CVE-2026-66583 is classified as CWE-502 and scored CVSS 3.1 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). It affects the WordPress Forminator plugin through 1.57.0 according to the title and description. The bundle does not document a required gadget chain, demonstrated code execution, technical root cause, or vendor-confirmed remediation.
Likely exposure
WordPress sites running Forminator 1.57.0 or earlier may be exposed, particularly when reachable from the internet. Confirm installed and active versions directly. The bundle’s structured affected entry lists versions as “n/a” and defaults to unaffected, conflicting with its title and description; treat exposure determination as requiring verification.
Exploitation context
The CVSS vector indicates remote, low-complexity, unauthenticated exploitation without user interaction. However, CVE-2026-66583 is not listed as KEV in the supplied bundle, and no cited evidence confirms active exploitation, a public proof of concept, or reliable exploitation in specific configurations.
Researcher notes
Available evidence is limited to a short vulnerability description, CWE-502 classification, CVSS vector, and Patchstack reference. The supplied structured affected data conflicts with the stated version range. Do not infer code execution or a usable gadget chain without additional evidence. Researchers should verify vendor advisories, affected code paths, prerequisites, and fixed-version details before drawing exploitability conclusions.
Mitigation direction
- Inventory WordPress sites and identify active Forminator versions.
- Check WPMU DEV and Patchstack guidance for a confirmed fixed release or mitigation.
- Prioritize remediation for internet-facing sites running version 1.57.0 or earlier.
- If remediation is unavailable, consider disabling Forminator after assessing operational impact.
- Monitor affected sites for suspicious requests, file changes, and administrative activity.
Validation and detection
- Confirm Forminator’s installed and active version on every WordPress instance.
- Verify remediated sites no longer run version 1.57.0 or earlier.
- Review vendor guidance to confirm the selected release addresses CVE-2026-66583.
- Examine security logs and integrity alerts for possible prior compromise.
- Re-scan affected assets after remediation and document remaining exceptions.
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-502: Code execution behavior lookup
Code execution and unsafe deserialization weaknesses often justify reviewing execution behavior and process telemetry. 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-2026-66583 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
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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.
SSVC decision data
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:N/UI:N/S:U/C:H/I:H/A:H3.95.9PatchstackVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://patchstack.com/database/wordpress/plugin/forminator/vulnerability/wordpress-forminator-plugin-1-57-0-php-object-injection-vulnerability?_s_id=cveCVE reference, Patchstack · vdb-entry
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.
Deserialization of Untrusted Data
Deserialization of Untrusted Data represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.