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

Quick assessment

Affected
Concrete CMS Concrete CMS
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

在 Concrete CMS 9.5.3 之前的版本中,SEO 批量更新元标签(Meta Tags)编辑器在保存前未检查目标页面的编辑权限。 操作虽然验证了针对该页面的 CSRF 令牌,但从未调用 来检查目标页面的编辑权限。因此,拥有批量 SEO 工具访问权限、且仅具备“查看”而非“编辑”某页面权限的用户,能够超出其编辑范围修改该页面的元标题、元描述和 URL 句柄,从而篡改原本受保护内容的展示信息和线上 URL。 Concrete CMS 安全团队根据 CVSS v4.0 标准将此漏洞评分定为 2.1,向量为:

CVSS 2.1 · Low

Possible ATT&CK Techniques 1 AI

T1190 · Exploit Public-Facing Application

Affected Version Matrix 1

VendorProduct Version RangeStatus
Concrete CMS Concrete CMS 5.0.0≤ 9.5.2 affected
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I. Basic Information for CVE-2026-81923

Vulnerability Information

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Vulnerability Title
Concrete CMS below 9.5.3 is missing authorization in the SEO Bulk Update Meta Tags editor
Source: CVE Program / CVE List V5
Vulnerability 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.
Source: CVE Program / CVE List V5
CVSS Information
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
Source: CVE Program / CVE List V5
Vulnerability Type
授权机制缺失
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
Concrete CMS Concrete CMS 5.0.0 ~ 9.5.2 -

II. Public POCs for CVE-2026-81923

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III. Intelligence Information for CVE-2026-81923

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Vendor Pages for CVE-2026-81923 (1)

Same Patch Batch · Concrete CMS · 2026-09-15 · 31 CVEs total

CVE-2026-18110 8.7 HIGH Concrete CMS 9.0.0 through 9.5.2 is vulnerable to missing authorization in the user select
CVE-2026-81894 8.5 HIGH Concrete CMS 9.5.2 and below is vulnerable to Stored DOM-based Cross-site Scripting (XSS)
CVE-2026-18111 8.5 HIGH Concrete CMS below 9.5.4 allows privilege escalation because adding users and assigning gr
CVE-2026-81895 8.5 HIGH Concrete CMS 9.5.2 and below is vulnerable to Stored SQL Injection in Concrete CMS Documen
CVE-2026-81896 8.4 HIGH Concrete CMS below version 9.5.3 is vulnerable to Stored XSS in Concrete CMS Form Submissi
CVE-2026-81897 7.7 HIGH Concrete CMS below version 9.5.3 is vulnerable to Stored XSS via Express form Text control
CVE-2026-81898 7.5 HIGH Concrete CMS below version 9.5.3 is vulnerable to Stored XSS via country-less Address att
CVE-2026-18113 7.5 HIGH Concrete CMS 9.0 to 9.5.2 is vulnerable to Stored XSS in the Top Navigation Bar Block via
CVE-2026-18115 7.4 HIGH In Concrete CMS 9.2.0 to 9.5.2, Missing Authorization in REST API Users update() and chang
CVE-2026-81899 7.3 HIGH Concrete CMS 9.0 to 9.5.2 is vulnerable to Stored XSS via group folder name on the Members
CVE-2026-68533 2.3 LOW Missing Authorization in Concrete CMS versions below 9.5.3 Conversation File Upload Allows
CVE-2026-81921 2.3 LOW In Concrete CMS 8.5.3 to 9,5,2, OAuth 2.0 Refresh-Token Grant Bypasses Account Status
CVE-2026-81920 2.3 LOW Concrete CMS below 9.5.3 is vulnerable to Cross-Site Request Forgery (CSRF) in Dashboard S
CVE-2026-68532 2.3 LOW Concrete CMS 9.0.0 to 9.5.2 is vunerable to CSRF in Concrete CMS Group Type Deletion Dashb
CVE-2026-68534 2.3 LOW Concrete CMS below 9.5.2 is vulnerable to Stored XSS via unescaped Express entry labels in
CVE-2026-81919 2.3 LOW Concrete CMS below 9.5.3 is vulnerable to Cross-Site Request Forgery (CSRF) in Block Arran
CVE-2026-81922 2.1 LOW "In Concrete CMS below 9.5.3, there is Missing authorization in the sitemap page reorder a
CVE-2026-81925 2.1 LOW Concrete CMS below 9.5.3 is vulnerable to Reflected Cross-Site Scripting (XSS) via Convers
CVE-2026-18424 2.1 LOW Concrete CMS 9.0.0 to 9.5.2 is vulnerable to SSRF protection bypass in remote file import
CVE-2026-18425 2.1 LOW IDOR in Concrete CMS 9.0.0 through 9.5.2 dashboard sitemap reorder (SitemapUpdate::updateD

Showing top 20 of 31 CVEs. View all on vendor page → →

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