CVE-2026-45016: EGroupware Local File Inclusion Vulnerability via file:// URI in Mail Compose
Summary
CVE-2026-45016: EGroupware Vulnerable to Local File Inclusion via file:// URI in Mail Compose. Affects egroupware/egroupware across 2 version ranges.
< 23.1.20260601
>= 26.0.20251208, < 26.5.20260507
Fixed in 23.1.20260601 or 26.5.20260507, depending on the release line you run. How to fix ↓
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Background
EGroupware is an open-source groupware application that provides a suite of tools for collaboration, including email, calendar, and task management. It is designed to enhance productivity and streamline communication within organizations. However, a critical vulnerability has been identified that allows authenticated users to exploit the system by including local files in email compositions, potentially leading to unauthorized access to sensitive information.
Vulnerability Detail
The vulnerability arises from the inadequate validation of URI schemes in the mail composition feature of EGroupware. Specifically, the function responsible for processing image URLs embedded in HTML emails fails to restrict the use of certain URI schemes. The check for HTTP URLs allows 'file://' URIs to bypass validation, enabling an attacker to read arbitrary files from the server's filesystem. This could lead to the exposure of sensitive files such as '/etc/passwd', application configuration files, and other critical data accessible by the web server process.
How To Fix
Fixed versions by release line
The minimum fixed version depends on the release line you run.
-
< 23.1.2026060123.1.20260601composer require egroupware/egroupware:23.1.20260601 -
>= 26.0.20251208, < 26.5.2026050726.5.20260507composer require egroupware/egroupware:26.5.20260507
Tip — Not sure which release line you're on? Vulert can find the fix for the version you are using. Scan free →
Workaround
As a temporary workaround, users can avoid using 'file://' URIs in their email compositions. However, this does not fully mitigate the risk and updating to a patched version is strongly recommended.
Conclusion
The CVE-2026-45016 vulnerability in EGroupware poses a significant risk by allowing local file inclusion through unvalidated URI schemes. It is crucial for users to update to the latest patched versions and implement the recommended code changes to safeguard their systems against potential exploitation.
See every vulnerability recorded for egroupware/egroupware →
FAQ
CVE-2026-45016 is a vulnerability in EGroupware that allows authenticated users to exploit local file inclusion via 'file://' URIs in email compositions.
You can check if your application is affected by using Vulert, which monitors open-source vulnerabilities in real-time. Visit Vulert Scanner to analyze your composer.lock file without any signup.
An attacker could read sensitive files from the server, including configuration files and user data, leading to potential data breaches.
You should upgrade to version 26.5.20260507 or later, or to version 23.1.20260601 or later to ensure that the vulnerability is patched.
If immediate updating is not possible, avoid using 'file://' URIs in email compositions as a temporary workaround until you can apply the patch.
References
Related vulnerabilities
Recent vulnerabilities recorded for egroupware/egroupware.
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