CVE-2012-5502: Cross-Site Scripting (XSS) Vulnerability in Plone
Summary
CVE-2012-5502: Plone Cross-site scripting Vulnerability. Affects plone across 2 version ranges.
< 4.2.3
>= 4.3a0, < 4.3b1
Fixed in 4.2.3 or 4.3b1, depending on the release line you run. How to fix ↓
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Background
Plone is an open-source content management system (CMS) written in Python and based on the Zope application server. It provides a user-friendly interface for managing and publishing content on websites. Plone is widely used for building websites, intranets, and web applications. However, versions before 4.2.3 and 4.3 before beta 1 are vulnerable to a cross-site scripting (XSS) attack.
Vulnerability Detail
The vulnerability exists in the safe_html.py module of Plone, allowing remote authenticated users with content editing permissions to inject arbitrary web script or HTML. The specific vectors through which the attack can be carried out are unspecified. This vulnerability can lead to the execution of malicious code in the context of the affected user, potentially compromising the confidentiality and integrity of the website or application.
How To Fix
Latest published version: 6.2.2 as of 23 Oct 2026
pip install --upgrade "plone==6.2.2"Upgrading to it may include breaking changes; the versions below are the minimum fixed release for this vulnerability.
If you can't move to the latest
The minimum fixed version depends on the release line you run.
-
< 4.2.34.2.3pip install --upgrade "plone==4.2.3" -
>= 4.3a0, < 4.3b14.3b1pip install --upgrade "plone==4.3b1"
Tip — Not sure which release line you're on? Vulert can find the fix for the version you are using. Scan free →
Workaround
No specific workaround has been mentioned for this vulnerability.
Conclusion
The cross-site scripting (XSS) vulnerability in Plone versions prior to 4.2.3 and 4.3 before beta 1 can allow remote authenticated users to inject arbitrary web script or HTML. Upgrading to the fixed versions of Plone will mitigate this vulnerability. For further support on vulnerability remediation, please contact DevNack.com.
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FAQ
Plone is an open-source content management system (CMS) written in Python and based on the Zope application server. It provides a user-friendly interface for managing and publishing content on websites.
Cross-site scripting (XSS) is a type of security vulnerability that allows attackers to inject malicious scripts into web pages viewed by other users. This can lead to the execution of arbitrary code in the context of the affected user, potentially compromising the security of the website or application.
An attacker with authenticated access and content editing permissions can exploit this vulnerability by injecting malicious web script or HTML into the affected Plone instance. This can be done through unspecified vectors, which may include input fields, forms, or other content editing interfaces.
The exploitation of this vulnerability can allow an attacker to execute arbitrary code in the context of the affected user. This can lead to various consequences, such as unauthorized access to sensitive information, manipulation of website content, and potential further exploitation of other vulnerabilities.
Yes, a fix is available for this vulnerability. It is recommended to upgrade to Plone version 4.2.3 or later if using a version prior to 4.2.3. For versions 4.3a0 and later, it is advised to upgrade to version 4.3b1 or later.
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