GHSA-ffq7-898w-9jc4 CVE-2026-40321
DotNetNuke.Core has stored cross-site-scripting (XSS) via SVG upload
High
NuGet
- Severity
- 8.0 / 10
- High · CVSS 3.1
- Exploit chance (EPSS)
- 6.41%
- Chance of exploitation in the next 30 days. Higher than 93.69% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-87 Improper Neutralization of Alternate XSS Syntax
- Fix
10.2.2- Upgrade DotNetNuke.Core to this version or later
Description
DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem. Prior to version 10.2.2, a user could upload a specially crafted SVG file that could include scripts that can target both authenticated and unauthenticated DNN users. The impact is increased if the scripts are run by a power user. Version 10.2.2 patches the issue.
Affected versions
NuGet
| Package | Vulnerable | Fixed in |
|---|---|---|
| DotNetNuke.Core | < 10.2.2 |
10.2.2 |
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.
DotNetNuke.Core NuGet → 10.2.2
- dotnet
dotnet add package DotNetNuke.Core --version 10.2.2
Severity breakdown
CVSS 3.1 8.0
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- Low
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Weakness
CWE-87: Improper Neutralization of Alternate XSS Syntax
The product does not neutralize or incorrectly neutralizes user-controlled input for alternate script syntax.
How to prevent it
- Implementation: Resolve all input to absolute or canonical representations before processing.
- 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 |
|---|---|---|
| CVE-2018-18325 Inadequate Encryption Strength in DotNetNuke | High Known exploited | Also affects DotNetNuke.Core |
| CVE-2018-15811 Inadequate Encryption Strength in DotNetNuke | High Known exploited | Also affects DotNetNuke.Core |
| GHSA-x2rg-fmcv-crq5 DNN (aka DotNetNuke) has Remote Code Execution via a cookie | High Known exploited | Also affects DotNetNuke.Core |
| GHSA-fcpv-w245-r2q7 DotNetNuke.Core security code analysis rules triggered | Low | Also affects DotNetNuke.Core |
| GHSA-2rhw-gw3f-477j DNN: Same HostGUID for all new installs | Medium | Also affects DotNetNuke.Core |
| GHSA-fpj4-9qhx-5m6m DNN: Force Friend Request Acceptance | Medium | Also affects DotNetNuke.Core |
| GHSA-w9pf-h6m6-v89h DotNetNuke.Core Vulnerable to Stored XSS via Module Title | Medium | Also affects DotNetNuke.Core |
| GHSA-vm5q-8qww-h238 DotNetNuke.Core Vulnerable to Stored XSS in Module Deletion Confirmation Modal | Medium | Also affects DotNetNuke.Core |
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