CVE-2026-105268 in Gitea
Summary
by MITRE • 10/07/2026
The Gitea API routes for issue attachments (`/api/v1/repos/{owner}/{repo}/issues/{index}/assets/{attachment_id}`) also accepted attachments that belong to comments on the issue. Because the author of an issue may edit and delete the issue's attachments, a user who opened an issue could rename or delete attachments that other users had posted in comments on that issue. The contents of the attachments could not be changed.
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability identified within Gitea represents a critical authorization flaw located specifically within the API endpoints responsible for managing issue attachments, namely /api/v1/repos/{owner}/{repo}/issues/{index}/assets/{attachment_id}. This security defect stems from an insufficient access control mechanism that fails to properly distinguish between assets directly attached to an issue and those associated with comments on said issue. In a correctly secured system, the scope of permissions granted to a user should be strictly limited by the ownership or creation context of the specific resource being accessed. However, in this instance, the API logic erroneously treats all attachments linked to an issue index as belonging solely to the primary issue author, thereby ignoring the distinct ownership boundaries established for comment-specific assets.
From a technical perspective, the flaw allows any user who has opened an issue to perform write operations on attachment resources that they do not own. Specifically, this includes the ability to rename or delete attachments uploaded by other users in response comments. While the vulnerability does not permit the modification of the actual file contents stored within these assets, the ability to alter metadata such as filenames and to remove files entirely constitutes a significant breach of integrity and availability principles. This behavior violates the fundamental security principle that an actor should only have access to resources they are explicitly authorized to manage, leading to what is classified under industry standards as CWE-269: Improper Privilege Management or more specifically CWE-862: Missing Authorization when applied to specific resource ownership contexts.
The operational impact of this vulnerability extends beyond simple data loss for individual users. It undermines the collaborative integrity of repository discussions by allowing a single participant to disrupt conversations through the deletion of evidence, such as logs, screenshots, or code snippets provided in comments. This can lead to confusion among team members who rely on these attachments for context and decision-making. Furthermore, it creates an environment where malicious actors could intentionally delete critical information posted by colleagues, effectively silencing contributions and degrading the trustworthiness of the platform's communication channels. The inability to modify file contents mitigates some risks related to data tampering or injection attacks via filename manipulation, but does not negate the severity of unauthorized deletion and renaming capabilities.
In terms of threat modeling, this vulnerability aligns with MITRE ATT&CK techniques involving resource hijacking or disruption of service through modification of user-generated content. It highlights a common pitfall in web application development where API endpoints are designed based on high-level entity relationships rather than granular permission checks for nested resources. The lack of validation to ensure that the requesting user is the owner of the specific attachment asset, as opposed to just the parent issue, represents a fundamental gap in input validation and access control logic within the Gitea codebase.
To mitigate this vulnerability, immediate action must be taken by upgrading to a patched version of Gitea where the authorization checks have been corrected to verify ownership at the individual attachment level rather than the issue level. For organizations unable to upgrade immediately, implementing a reverse proxy or Web Application Firewall rule that restricts write access to these specific API endpoints based on strict identity verification can provide temporary relief. Additionally, developers should review their own integrations with Gitea APIs to ensure they are not relying on this behavior for any legitimate business logic and adjust permissions accordingly until the patch is applied. Regular security audits focusing on nested resource authorization patterns in RESTful APIs are recommended to prevent similar flaws from being introduced in future development cycles.