CVE-2026-78433
Deferred Deferred - Pending Action

Gitea Attachment Handler Path Traversal Vulnerability

Vulnerability report for CVE-2026-78433, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-10-14

Last updated on: 2026-10-18

Assigner: Gitea Limited

Description

Gitea's web attachment handler skips its cross-repository ownership check for attachments created before 16 January 2026 and checks permissions against the repository named in the request URL instead. An unauthenticated attacker who knows a private attachment's UUID can request it through a public repository's attachment path and retrieve its contents. This can expose issue and pull request attachments or release assets; the random attachment UUID must already be known to the attacker.

CVSS Scores

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Meta Information

Published
2026-10-14
Last Modified
2026-10-18
Generated
2026-10-19
AI Q&A
2026-10-15
EPSS Evaluated
2026-10-18
NVD
EUVD

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
Gitea Gitea 1.26.0

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-284 The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
CWE-639 The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
CWE-863 The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
CWE-1220 The product implements access controls via a policy or other feature with the intention to disable or restrict accesses (reads and/or writes) to assets in a system from untrusted agents. However, implemented access controls lack required granularity, which renders the control policy too broad because it allows accesses from unauthorized agents to the security-sensitive assets.

Attack-Flow Graph

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Executive Summary

CVE-2026-78433 is a vulnerability in Gitea where the web attachment handler fails to properly check repository ownership for attachments created before January 16, 2026. Instead of verifying permissions against the attachment's actual repository, it checks against the repository in the request URL. This allows unauthenticated attackers who know a private attachment's UUID to access it through a public repository's attachment path.

Detection Guidance

Check Gitea version with 'gitea --version' to confirm if it is below 1.27.3. Inspect web server logs for suspicious attachment requests across repositories. Look for patterns where private attachment UUIDs are accessed via public repository paths.

Impact Analysis

This vulnerability could expose sensitive data such as issue attachments, pull request files, or release assets from private repositories. Attackers need only the attachment UUID to retrieve the content, which could lead to data leaks or unauthorized access to confidential information.

Compliance Impact

This vulnerability could lead to unauthorized access to personal or sensitive data, potentially violating GDPR, HIPAA, or other privacy regulations. Organizations using affected Gitea versions may face compliance risks due to potential data breaches.

Mitigation Strategies

Upgrade Gitea to version 1.27.3 or later immediately. Review and restrict access to attachments created before January 2026. Monitor for unauthorized access attempts to attachments.

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