CVE-2026-34212
Stored XSS in Docmost Attachment URLs Allows Script Execution
Publication date: 2026-04-14
Last updated on: 2026-04-22
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| docmost | docmost | to 0.71.0 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-79 | The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. |
Attack-Flow Graph
AI Powered Q&A
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
This vulnerability allows a low-privileged authenticated user to inject malicious JavaScript via attachment URLs, which executes in the context of the Docmost origin when other users activate the link. Such cross-site scripting (XSS) issues can lead to unauthorized access to user data or session information.
Because of the potential for unauthorized data access or manipulation, this vulnerability could negatively impact compliance with data protection regulations such as GDPR or HIPAA, which require safeguarding personal and sensitive information against unauthorized access or disclosure.
Organizations using vulnerable versions of Docmost may face increased risk of data breaches or unauthorized data exposure, which could lead to non-compliance with these standards.
Can you explain this vulnerability to me?
This vulnerability exists in Docmost, an open-source collaborative wiki and documentation software, in versions prior to 0.71.0. It involves improper neutralization of attachment URLs, which allows a low-privileged authenticated user to insert a malicious `javascript:` URL inside an attachment node within page content.
When another user views the affected page and activates the attachment link or icon, the attacker-controlled JavaScript executes in the context of the Docmost origin, potentially leading to unauthorized actions or data exposure.
This issue was fixed in version 0.71.0.
How can this vulnerability impact me? :
The vulnerability can lead to execution of attacker-controlled JavaScript code in the context of the Docmost application when a user activates a malicious attachment link.
This can result in unauthorized actions such as data theft, session hijacking, or manipulation of the application on behalf of the victim user.
Since the attacker needs only low-privileged authenticated access to insert the malicious URL, the risk is elevated within environments where multiple users have editing rights.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, upgrade Docmost to version 0.71.0 or later, as this version patches the issue.