5.7
MEDIUM CVSS 3.1
CVE-2026-44696
OpenProject: Stored CSS injection via Sanitize::Config::RELAXED[:css] enables phishing overlays and data exfiltration
Description

OpenProject is open-source, web-based project management software. Prior to 17.4.0, OpenProject's rich text (markdown) rendering pipeline uses Sanitize::Config::RELAXED[:css] for inline style sanitization. This configuration permits essentially all CSS properties in style attributes on permitted HTML elements (figure, img, table, th, tr, td). This allows any authenticated user with write access to formattable text fields (work package descriptions, comments, project descriptions, news) to inject CSS This vulnerability is fixed in 17.4.0.

INFO

Published Date :

June 26, 2026, 8:17 p.m.

Last Modified :

June 27, 2026, 4:17 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-44696 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Openproject openproject
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 MEDIUM [email protected]
Solution
Update OpenProject to version 17.4.0 or later to fix the CSS injection vulnerability.
  • Update OpenProject to version 17.4.0 or later.
  • Apply security patches provided by the vendor.
  • Review and restrict CSS properties in user-generated content.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-44696.

URL Resource
https://github.com/opf/openproject/security/advisories/GHSA-j9q2-49mp-hmq5
https://github.com/opf/openproject/security/advisories/GHSA-j9q2-49mp-hmq5
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-44696 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-44696 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-44696 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-44696 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jun. 27, 2026

    Action Type Old Value New Value
    Added Reference https://github.com/opf/openproject/security/advisories/GHSA-j9q2-49mp-hmq5
    Added SSVC {'id': 'CVE-2026-44696', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-06-27T03:02:09.710397Z'}
  • New CVE Received by [email protected]

    Jun. 26, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'opf', 'product': 'openproject', 'versions': [{'status': 'affected', 'version': '< 17.4.0'}]}]
    Added Description OpenProject is open-source, web-based project management software. Prior to 17.4.0, OpenProject's rich text (markdown) rendering pipeline uses Sanitize::Config::RELAXED[:css] for inline style sanitization. This configuration permits essentially all CSS properties in style attributes on permitted HTML elements (figure, img, table, th, tr, td). This allows any authenticated user with write access to formattable text fields (work package descriptions, comments, project descriptions, news) to inject CSS This vulnerability is fixed in 17.4.0.
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N
    Added CWE CWE-79
    Added Reference https://github.com/opf/openproject/security/advisories/GHSA-j9q2-49mp-hmq5
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.