EUVD-2026-9850

Comprehensive Technical Analysis of EUVD-2026-9850

1. Vulnerability Assessment and Severity Evaluation

The vulnerability EUVD-2026-9850, also known as CVE-2026-25921 and GHSA-cj4v-437j-jq4c, affects the Gogs Git service. The issue is a cross-repository LFS (Large File Storage) object overwrite due to missing content hash verification. This vulnerability has a CVSS (Common Vulnerability Scoring System) base score of 9.3, indicating a critical severity level. The CVSS vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:L breaks down as follows:

• Attack Vector (AV): Network (N) - The vulnerability is exploitable over the network.
• Attack Complexity (AC): Low (L) - The attack requires low complexity to exploit.
• Privileges Required (PR): None (N) - No privileges are required to exploit the vulnerability.
• User Interaction (UI): None (N) - No user interaction is required.
• Scope (S): Changed (C) - The vulnerability affects a different security scope.
• Confidentiality (C): None (N) - There is no impact on confidentiality.
• Integrity (I): High (H) - There is a high impact on integrity.
• Availability (A): Low (L) - There is a low impact on availability.

2. Potential Attack Vectors and Exploitation Methods

The primary attack vector involves exploiting the lack of content hash verification in the LFS objects. An attacker could potentially:

• Overwrite LFS Objects: By manipulating the LFS objects, an attacker could overwrite existing objects in different repositories, leading to data corruption or unauthorized data modification.
• Inject Malicious Content: An attacker could inject malicious content into LFS objects, which could then be propagated across different repositories, affecting multiple projects.

Exploitation methods could include:

• Network-Based Attacks: Since the attack vector is network-based, an attacker could exploit this vulnerability remotely without needing physical access to the system.
• Automated Scripts: Attackers could use automated scripts to scan for vulnerable Gogs instances and exploit the vulnerability en masse.

3. Affected Systems and Software Versions

The vulnerability affects Gogs versions prior to 0.14.2. Organizations and individuals using Gogs for version control and repository management should ensure they are running version 0.14.2 or later to mitigate this risk.

4. Recommended Mitigation Strategies

To mitigate the risk associated with this vulnerability, the following steps are recommended:

• Update Software: Immediately update Gogs to version 0.14.2 or later. This update includes the necessary fixes to address the missing content hash verification issue.
• Monitor Network Traffic: Implement network monitoring to detect any unusual activity that may indicate an attempt to exploit this vulnerability.
• Access Controls: Enforce strict access controls and authentication mechanisms to limit unauthorized access to repositories.
• Regular Audits: Conduct regular security audits and vulnerability assessments to identify and address potential security weaknesses.

5. Impact on European Cybersecurity Landscape

The European cybersecurity landscape could be significantly impacted by this vulnerability, particularly for organizations that rely on Gogs for version control and repository management. The potential for data corruption and unauthorized data modification poses a serious risk to the integrity and availability of critical systems. Organizations in sectors such as finance, healthcare, and government, which handle sensitive data, are particularly at risk.

6. Technical Details for Security Professionals

For security professionals, the following technical details are pertinent:

• Vulnerability Identification: The vulnerability is identified by the lack of content hash verification in LFS objects, which allows for cross-repository object overwrites.
• Code Review: Review the changes made in the GitHub pull request #8166 and the commit 81ee8836445ac888d99da8b652be7d5cbc5c4d5c for a detailed understanding of the fix.
• Testing: Conduct thorough testing of the updated Gogs version to ensure that the vulnerability has been effectively mitigated and that no new issues have been introduced.
• Incident Response: Develop an incident response plan that includes steps for identifying, containing, and remediating any exploitation of this vulnerability.

By addressing this vulnerability promptly and comprehensively, organizations can protect their systems and data from potential exploitation and ensure the continued integrity and availability of their repositories.