CVE-2026-16027
Received Received - Intake

SSRF Vulnerability in Türkiye's E-Signature

Publication date: 2026-08-07

Last updated on: 2026-08-07

Assigner: Computer Emergency Response Team of the Republic of Turkey

Description
Server-Side request forgery (SSRF) vulnerability in Revenue Administration Türkiye's E-Signature allows Server Side Request Forgery. This issue affects Türkiye's E-Signature: from 2.4.4.0 before 2.5.1.0.

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Meta Information

Published
2026-08-07
Last Modified
2026-08-07
Generated
2026-08-07
AI Q&A
2026-08-07
EPSS Evaluated
N/A
NVD
CVE-2026-16027
EUVD
EUVD-2026-54397

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
türkiye e-signature From 2.4.4.0 (inc) to 2.5.1.0 (exc)

Helpful Resources

Exploitability

CWE
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KEV
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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.

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Executive Summary

This is a Server-Side Request Forgery (SSRF) vulnerability in Revenue Administration Türkiye's E-Signature software. It allows an attacker to trick the server into making unauthorized requests to internal or external systems. The flaw exists in versions before 2.5.1.0.

Detection Guidance

Detecting SSRF vulnerabilities typically involves monitoring network traffic for unusual requests, checking server logs for outbound connections to unexpected internal or external addresses, and validating input parameters that may trigger server-side requests. Specific commands depend on your infrastructure but may include network scanners, log analysis tools, or web application firewalls.

Impact Analysis

An attacker could exploit this to access internal systems, steal sensitive data, or perform unauthorized actions on behalf of the server. It may lead to data breaches or service disruption if exploited.

Compliance Impact

SSRF vulnerabilities can lead to unauthorized data access, violating GDPR's data protection principles and HIPAA's security rules. Compliance may be compromised if sensitive data is exposed due to exploitation.

Mitigation Strategies

Immediately update the E-Signature software to version 2.5.1.0 or later. Disable unnecessary network services, restrict outbound connections from the server, and implement input validation for server-side requests. Review and update firewall rules to block unauthorized outbound traffic.

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