Medium · CVSS 6.5CVE-2026-19856

All in One SEO < 5.0.2.1 - Unauthenticated Arbitrary Shortcode Execution via Search Query

Answer in brief

CVE-2026-19856 records a Medium severity (CVSS 6.5) vulnerability in All in One SEO < 5.0.2.1 - Unauthenticated Arbitrary Shortcode Execution via Search Query. The current sources do not mark it as known exploited. The current feed maps Unknown/All in One SEO (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 Oct 2, 2026Updated Oct 2, 2026Source checked Oct 2, 2026First seen by HOL Oct 2, 2026Material review Oct 2, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 6.5
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 6.5. 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/All in One SEO (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Unknown/All in One SEOgeneric	>=0 <5.0.2.1	5.0.2.1

Recommended response

Check inventory. Check lockfiles and deployed manifests for Unknown/All in One SEO.
Review the reported fix. Update Unknown/All in One SEO to 5.0.2.1 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 2, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 2, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 2, 2026

Sources and claim methodology

Source referencewpscan.com

Upstream source description

The All in One SEO WordPress plugin before 5.0.2.1 does not correctly determine which shortcodes are present in content derived from user input before deciding which ones to strip, allowing unauthenticated users to execute arbitrary shortcodes registered on the site. On sites upgraded from older versions the protection is disabled outright, making the issue reachable without any crafted input.

Quoted source text, attributed separately from HOL analysis.