CVE-2026-49865

Received Received - Intake

Server-Side Request Forgery in Kimai Time Tracking App

Publication date: 2026-09-11

Last updated on: 2026-09-11

Assigner: GitHub, Inc.

Description

Kimai is an open-source time tracking application. Versions prior to 2.58.0 contain a server-side request forgery vulnerability in their invoice PDF preview and generation workflow. If an attacker can control Markdown content that is later rendered into an invoice PDF, such as `Customer.invoiceText`, the server-side PDF renderer will fetch remote image URLs embedded in Markdown image syntax. This allows the application server to issue outbound requests to attacker-controlled or internal targets during PDF rendering. The behavior can be used for internal network probing, server-side reachability checks, and potentially follow-on exploitation depending on deployment environment and accessible internal services. Version 2.58.0 patches the issue.

CVSS Scores

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Meta Information

Published

2026-09-11

Last Modified

2026-09-11

Generated

2026-09-12

AI Q&A

2026-09-12

EPSS Evaluated

N/A

NVD

CVE-2026-49865

Affected Vendors & Products

Vendor	Product	Version / Range
kimai	kimai	to 2.58.0 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-918	The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.

Attack-Flow Graph

Executive Summary

This is a server-side request forgery (SSRF) vulnerability in Kimai, an open-source time tracking application. Versions before 2.58.0 allow attackers to control Markdown content that is rendered into invoice PDFs. The PDF renderer then fetches remote image URLs embedded in the Markdown, causing the server to make outbound requests to attacker-controlled or internal targets during PDF generation.

Detection Guidance

Check for outbound HTTP requests during PDF generation by monitoring network traffic when invoices are rendered. Look for unexpected connections to internal or external IPs from the Kimai server. Review logs for Markdown content containing image URLs in invoice fields like Customer.invoiceText.

Impact Analysis

An attacker could use this to probe your internal network, check server reachability, or potentially exploit other internal services depending on your deployment environment. This could lead to unauthorized access or data exposure if internal systems are vulnerable.

Compliance Impact

This vulnerability could violate compliance requirements by allowing unauthorized network access or data exfiltration. GDPR and HIPAA require protecting personal and health data, and an SSRF flaw could enable breaches of confidentiality or integrity of such data.

Mitigation Strategies

Upgrade Kimai to version 2.58.0 or later to patch the vulnerability. If immediate upgrade is not possible, restrict access to invoice generation features and sanitize Markdown input to prevent embedded image URLs. Monitor outbound traffic from the Kimai server for suspicious activity.

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