GHSA-f73j-pm2c-rxvr CVE-2026-8245
Concrete CMS is Vulnerable to Reflected XSS in Legacy Pagination
Medium
Packagist
- Severity
- 0.0 / 10
- Medium · CVSS 4.0
- Exploit chance (EPSS)
- 0.14%
- Chance of exploitation in the next 30 days. Higher than 3.26% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-83 Improper Neutralization of Script in Attributes in a Web Page
- Fix
9.5.1- Upgrade concrete5/concrete5 to this version or later
Description
Concrete CMS 9.5.0 and below is vulnerable to Reflected XSS in Legacy Pagination via HTML attribute injection. Concrete\Core\Legacy\Pagination builds pagination links by raw-interpolating its $URL field into href="" (<a href="{$linkURL}" …>). Any authenticated admin or report viewer with access to /dashboard/reports/forms/legacy who clicks the crafted URL fires the payload in their session.
Affected versions
Packagist
| Package | Vulnerable | Fixed in |
|---|---|---|
| concrete5/concrete5 | < 9.5.1 |
9.5.1 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
concrete5/concrete5 Packagist → 9.5.1
- composer
composer require concrete5/concrete5:^9.5.1
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- Present
- Privileges required
- None
- User interaction
- Passive
- Confidentiality (vulnerable system)
- High
- Integrity (vulnerable system)
- Low
- Availability (vulnerable system)
- None
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
CVSS 3.1 5.4
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Weakness
CWE-83: Improper Neutralization of Script in Attributes in a Web Page
The product does not neutralize or incorrectly neutralizes "javascript:" or other URIs from dangerous attributes within tags, such as onmouseover, onload, onerror, or style.
How to prevent it
- Implementation: Carefully check each input parameter against a rigorous positive specification (allowlist) defining the specific characters and format allowed. All input should be neutralized, not just parameters that the user is supposed to specify, but all data in the request, including tag attributes, hidden fields, cookies, headers, the URL itself, and so forth. A common mistake that leads to continuing XSS vulnerabilities is to validate only fields that are expected to be redisplayed by the site. We often encounter data from the request that is reflected by the application server or the application that the development team did not anticipate. Also, a field that is not currently reflected may be used by a future developer. Therefore, validating ALL parts of the HTTP request is recommended.
- Implementation: Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8. When an encoding is not specified, a downstream component may choose a different encoding, either by assuming a default encoding or automatically inferring which encoding is being used, which can be erroneous. When the encodings are inconsistent, the downstream component might treat some character or byte sequences as special, even if they are not special in the original encoding. Attackers might then be able to exploit this discrepancy and conduct injection attacks; they even might be able to bypass protection mechanisms that assume the original encoding is also being used by the downstream component. The problem of inconsistent output encodings often arises in web pages. If an encoding is not specified in an HTTP header, web browsers often guess about which encoding is being used. This can open up the browser to subtle XSS attacks.
- Implementation: With Struts, write all data from form beans with the bean's filter attribute set to true.
- Implementation: To help mitigate XSS attacks against the user's session cookie, set the session cookie to be HttpOnly. In browsers that support the HttpOnly feature (such as more recent versions of Internet Explorer and Firefox), this attribute can prevent the user's session cookie from being accessible to malicious client-side scripts that use document.cookie. This is not a complete solution, since HttpOnly is not supported by all browsers. More importantly, XmlHttpRequest and other powerful browser technologies provide read access to HTTP headers, including the Set-Cookie header in which the HttpOnly flag is set.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-g82f-9pw7-773w Concrete CMS: PHP Object Injection via unserialize() calls | High | Also affects concrete5/concrete5 |
| GHSA-52pr-7vmf-2w7x Concrete CMS is vulnerable to PHP Object Injection via unserialize() calls in the Workflow, Form block, and File/Set components | High | Also affects concrete5/concrete5 |
| GHSA-q9fm-mpg8-8jqm Concrete CMS is vulnerable to Stored XSS via page name in the Atomik theme | Medium | Also affects concrete5/concrete5 |
| GHSA-jqvq-gv67-3567 Concrete CMS is vulnerable to IDOR + wrong-authorization-level in the Express association Reorder dialog | Medium | Also affects concrete5/concrete5 |
| GHSA-xjg6-5v39-v7fc Concrete CMS is vulnerable to CSRF via Backend\File::approveVersion | Medium | Also affects concrete5/concrete5 |
| GHSA-44q4-354f-c826 Concrete CMS is vulnerable to Cross Site Request Forgery (CSRF) at concrete/controllers/backend/file approveVersion() | Medium | Also affects concrete5/concrete5 |
| GHSA-6qjh-p324-694f Concrete CMS is vulnerable to Cross Site Request Forgery (CSRF) at concrete/controllers/backend/file rescanMultiple() | High | Also affects concrete5/concrete5 |
| GHSA-6fxm-r8p3-mx5c Concrete CMS is vulnerable to Cross Site Request Forgery (CSRF) at concrete/controllers/backend/file rescan() | High | Also affects concrete5/concrete5 |
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