Security readout for executives and security teams
Plain-English summary
A flaw in the Embed HTML5 Game WordPress plugin through version 1.3 may let any internet user upload a PHP backdoor without logging in. Successful abuse could give an attacker control over the website, expose data, alter content, and disrupt service.
Executive priority
Act immediately on public-facing affected sites. Disable the plugin or isolate its upload functionality, investigate for compromise, and restore service only after authoritative remediation is verified. Prioritize sites holding sensitive data or supporting critical operations.
Technical view
CVE-2026-4357 is a CWE-434 unrestricted file-upload vulnerability. The plugin inadequately validates both uploader authorization and uploaded file types. CVSS 3.1 rates it 10.0 because remote, unauthenticated exploitation requires low complexity and no user interaction, with potentially severe confidentiality, integrity, and availability impact.
Likely exposure
Internet-accessible WordPress sites running Embed HTML5 Game version 1.3 or earlier are potentially exposed. The sources do not identify required configuration, the vulnerable request path, reliable version-detection methods, or whether every installation exposes the upload function.
Exploitation context
WPScan labels its reference as containing exploit information, but the supplied evidence does not establish active exploitation. The CVE is not listed as KEV in the bundle. Treat exposed installations as urgent because unauthenticated PHP upload could enable complete site compromise.
Researcher notes
The record supports an unauthenticated arbitrary PHP-file upload affecting versions through 1.3. It does not provide the vulnerable endpoint, code-level root cause, affected configuration details, fixed version, vendor identity, observed exploitation, or forensic indicators. The structured affected-version entry is inconsistent with the narrative and lists only version "0," reducing precision.
Mitigation direction
- Identify and prioritize sites running Embed HTML5 Game version 1.3 or earlier.
- Disable or remove the plugin until authoritative vendor remediation guidance is confirmed.
- Restrict public access to relevant upload functionality where operationally feasible.
- Review vendor and WordPress security guidance for a fixed release or approved mitigation.
- Investigate potentially exposed sites for compromise before restoring the plugin.
Validation and detection
- Inventory WordPress installations and record the plugin's installed and active versions.
- Confirm whether plugin upload functionality is reachable without authentication.
- Review web and security logs for suspicious unauthenticated upload activity.
- Inspect writable web directories for unexpected or recently created PHP files.
- Verify remediation prevents unauthenticated uploads without using offensive payloads.
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-434: File access and web shell behavior lookup
File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection 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 lookupFile access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-4357 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
- 10 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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:C/C:H/I:H/A:H3.96WPScanVulnerability scoring details
Base CVSS 3.1 score
10CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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://wpscan.com/vulnerability/b364969d-9dac-46ce-83e2-fc0fc2e5f698/CVE reference, WPScan · exploit, 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.
Unrestricted Upload of File with Dangerous Type
Unrestricted Upload of File with Dangerous Type represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.