CVE-2026-123184 in Altium
Summary
by MITRE • 11/05/2026
An incorrect authorization vulnerability exists in the Altium 365 Git Service. The permission check performed when a user pushes to a project repository did not correctly evaluate the required access level, so the check passed for any user holding any level of access to the project. As a result, an authenticated user with view-only access to a project could write to that project's git repository.
Read access was evaluated correctly and was not affected, and exploitation requires an authenticated account with existing access to the target project. The issue has been remediated in Altium 365 at the service level and no customer action is required. On-premise Altium Enterprise Server is not affected.
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Analysis
by VulDB Data Team • 11/05/2026
The vulnerability identified within the Altium 365 Git Service represents a critical failure in access control logic, specifically categorized under CWE-284 Improper Access Control. This flaw manifests during the authentication and authorization phase of git operations, where the system fails to enforce strict role-based permissions for write actions. While read operations are correctly validated against user privileges, the mechanism governing push events contains a logical error that bypasses necessary permission checks. Consequently, any authenticated user who possesses at least view-only access to a specific project is granted unauthorized write capabilities to its associated git repository. This discrepancy allows individuals with minimal initial permissions to modify source code history, commit changes, and potentially introduce malicious or erroneous content into the version control system without proper authorization.
From an operational perspective, this vulnerability poses significant risks to software integrity and supply chain security. An attacker leveraging this flaw could perform unauthorized commits that alter project configurations, inject backdoors, or corrupt build artifacts. Such actions can lead to severe consequences including compromised builds, deployment of vulnerable code to production environments, and disruption of development workflows. The ability to write to a repository without elevated privileges undermines the principle of least privilege, which is fundamental to secure software engineering practices. Furthermore, this type of vulnerability aligns with MITRE ATT&CK technique T1078 Valid Accounts, as exploitation requires an authenticated session, but it specifically exploits the failure in authorization logic rather than credential theft or compromise.
The scope of this issue is limited to cloud-hosted instances of Altium 365 and does not affect on-premise deployments such as Altium Enterprise Server. This distinction highlights that the flaw resides within the specific service layer handling git operations for the SaaS offering, likely due to a misconfiguration or coding error in the authorization middleware rather than a fundamental architectural weakness shared across all deployment models. Exploitation is contingent upon an attacker possessing valid credentials with at least read access to the target project, meaning that unauthenticated remote exploitation is not possible through this specific vector.
Remediation has been implemented by Altium at the service level for cloud users, effectively closing the authorization gap without requiring any action from individual customers or administrators of affected projects. This proactive patching approach ensures that existing sessions and future interactions are governed by corrected permission logic immediately upon update propagation. For organizations relying on version control systems, this incident underscores the importance of regular security audits focusing on access control lists and role definitions. It also reinforces the need for continuous monitoring of git repository activities to detect any anomalous write operations from users with unexpectedly elevated privileges, serving as a defensive measure even after technical patches are applied.