CVE-2025-68971: Forgejo DoS Vulnerability via Upload

CVE-2025-68971 Overview

In Forgejo through version 13.0.3, a denial of service vulnerability exists in the attachment component. The vulnerability allows authenticated attackers to upload multi-gigabyte file attachments that can be associated with issues or releases, potentially exhausting server resources and causing service disruption for legitimate users.

Critical Impact
Authenticated users can exhaust server storage and memory resources by uploading extremely large file attachments, leading to denial of service conditions that affect all users of the Forgejo instance.

Affected Products

Forgejo versions through 13.0.3
Forgejo attachment component (issues and releases functionality)

Discovery Timeline

2026-03-16 - CVE-2025-68971 published to NVD
2026-03-17 - Last updated in NVD database

Technical Details for CVE-2025-68971

Vulnerability Analysis

This vulnerability is classified as CWE-400 (Uncontrolled Resource Consumption), a resource exhaustion vulnerability that occurs when the Forgejo attachment component fails to properly validate or limit the size of uploaded file attachments. The attack can be executed over the network by any authenticated user with permissions to create issues or releases.

The vulnerability requires low attack complexity and no user interaction to exploit. While the confidentiality and integrity of the system remain unaffected, the availability impact is significant. An attacker can repeatedly upload extremely large files (multi-gigabyte in size) to overwhelm server storage capacity, consume excessive memory during file processing, and degrade or completely disrupt service for all legitimate users.

Root Cause

The root cause of this vulnerability lies in insufficient input validation within the attachment upload functionality. Forgejo through version 13.0.3 does not implement adequate file size restrictions or upload rate limiting for attachments associated with issues and releases. This allows attackers to bypass normal resource management controls and consume disproportionate amounts of server resources through oversized file uploads.

Attack Vector

The attack is network-based and requires the attacker to have low-level privileges (authenticated user access). An attacker can exploit this vulnerability by:

Authenticating to a vulnerable Forgejo instance
Creating or accessing an issue or release
Uploading one or more extremely large file attachments (multi-gigabyte files)
Repeating the process to exhaust available storage space and processing resources

The lack of proper file size validation allows these oversized uploads to proceed unchecked, consuming disk space and potentially causing memory exhaustion during file handling operations. This can result in degraded performance for all users or complete service unavailability.

Detection Methods for CVE-2025-68971

Indicators of Compromise

Unusually large files appearing in Forgejo attachment storage directories
Rapid consumption of disk space on servers hosting Forgejo instances
Multiple large file upload requests from single user accounts in short time periods
Server resource alerts indicating storage capacity approaching limits

Detection Strategies

Monitor attachment upload sizes and flag uploads exceeding normal thresholds
Implement logging for all attachment upload operations with file size metadata
Configure alerts for disk utilization spikes on Forgejo server storage volumes
Review access logs for patterns of repeated large file uploads from individual accounts

Monitoring Recommendations

Establish baseline metrics for typical attachment sizes in your Forgejo deployment
Set up automated alerts when upload sizes exceed organizational thresholds
Monitor server disk space utilization with alerts at 80% and 90% capacity thresholds
Track per-user upload volume to identify potential abuse patterns

How to Mitigate CVE-2025-68971

Immediate Actions Required

Review current Forgejo version and upgrade if running version 13.0.3 or earlier
Audit recent attachment uploads to identify any suspiciously large files
Implement web server or reverse proxy level file size limits as an interim measure
Monitor disk space utilization on Forgejo servers for unexpected consumption

Patch Information

Organizations should monitor the Forgejo Code Repository for security updates addressing this vulnerability. Additional technical details and related datasets are available at FreeBSD Bug Report #291973, Zenodo Dataset #18945481, and Zenodo Dataset #19058493.

Workarounds

Configure web server (nginx/Apache) upload size limits to restrict maximum file sizes before they reach Forgejo
Implement reverse proxy rules to reject oversized upload requests
Review and restrict user permissions for creating issues and releases to trusted accounts only
Set up disk quotas on storage volumes used by Forgejo to limit impact of resource exhaustion attacks

bash

# Example nginx configuration to limit upload size
# Add to server or location block
client_max_body_size 50M;

# Example Apache configuration
LimitRequestBody 52428800