Low · CVSS 2.1CVE-2026-81923

Concrete CMS below 9.5.3 is missing authorization in the SEO Bulk Update Meta Tags editorCVE-2026-81923

Answer in brief

CVE-2026-81923 records a Low severity (CVSS 2.1) vulnerability in Concrete CMS below 9.5.3 is missing authorization in the SEO Bulk Update Meta Tags editor. The current sources do not mark it as known exploited. The current feed maps Concrete CMS/Concrete CMS (generic), Concrete CMS/Concrete CMS (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 15, 2026Updated Sep 18, 2026Source checked Oct 30, 2026First seen by HOL Sep 15, 2026Material review Sep 18, 2026

Upstream Advisory

Key facts

Risk: Low · CVSS 2.1
Exploitation: Not marked as known exploited
Affected software: 3 mapped packages or products
Fix availability: Not reported

Why this deserves its current priority

CVSS is 2.1. 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 Concrete CMS/Concrete CMS (generic), Concrete CMS/Concrete CMS (generic). Check affected ranges and fixed versions before updating.

Affected products and reported versions
Product	Affected versions	Fixed versions
cpe:2.3:a:concretecms:concrete_cms::::::::	Not reported	Not reported

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Concrete CMS/Concrete CMSgeneric	5.0.0	Not reported
Concrete CMS/Concrete CMSgeneric	>=5.0.0 <=9.5.2	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Concrete CMS/Concrete CMS, Concrete CMS/Concrete CMS.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 18, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 15, 2026

Sources and claim methodology

Source referencedocumentation.concretecms.org

Upstream source description

In Concrete CMS before 9.5.3, the SEO Bulk Update Meta Tags editor did not check per-page edit permissions before saving. The saveRecord() action validated the per-page CSRF token but never called canEditPageProperties() for the target page, so a user who was granted access to the bulk SEO tool and could view (but not edit) a given page was able to change that page's meta title, meta description, and URL handle outside their edit scope, tampering with the presentation and live URLs of otherwise protected content. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 2.1 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Andrew Gonzalez for reporting.

Quoted source text, attributed separately from HOL analysis.