PostX < 5.0.41 - Unauthenticated Custom Field Key Disclosure via REST API (CVE-2026-86783) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-86783

PostX < 5.0.41 - Unauthenticated Custom Field Key Disclosure via REST API

Answer in brief

CVE-2026-86783 records a Unknown severity vulnerability in PostX < 5.0.41 - Unauthenticated Custom Field Key Disclosure via REST API. The current sources do not mark it as known exploited. The current feed maps Unknown/Post Grid Gutenberg Blocks (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 23, 2026Updated Sep 23, 2026Source checked Sep 23, 2026First seen by HOL Sep 23, 2026Material review Sep 23, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Unknown/Post Grid Gutenberg Blocks (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Unknown/Post Grid Gutenberg Blocksgeneric	>=0 <5.0.41	5.0.41

Recommended response

Check inventory. Check lockfiles and deployed manifests for Unknown/Post Grid Gutenberg Blocks.
Review the reported fix. Update Unknown/Post Grid Gutenberg Blocks to 5.0.41 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 23, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 23, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 23, 2026

Sources and claim methodology

Source referencewpscan.com

Upstream source description

The Post Grid Gutenberg Blocks WordPress plugin before 5.0.41 does not perform an authorization or post-visibility check on a REST API route that returns the custom field keys of a given post, allowing unauthenticated users to disclose the custom field key names of arbitrary posts, including private, draft, pending, scheduled and password-protected posts.

Quoted source text, attributed separately from HOL analysis.