CVE-2026-25575
📋 TL;DR
CVE-2026-25575 is a path traversal vulnerability in NavigaTUM's propose_edits endpoint that allows unauthenticated attackers to overwrite files in writable directories. This could lead to defacement of public images or filling server storage. All NavigaTUM instances prior to commit 86f34c7 are affected.
💻 Affected Systems
- NavigaTUM
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete server compromise via file overwrite leading to remote code execution, data destruction, or persistent backdoor installation.
Likely Case
Website defacement by replacing public images, denial of service by filling storage, or data corruption.
If Mitigated
No impact if proper input validation and directory restrictions are implemented.
🎯 Exploit Status
Simple HTTP POST with crafted JSON payload containing path traversal sequences.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Commit 86f34c72886a59ec8f1e6c00f78a5ab889a70fd0
Vendor Advisory: https://github.com/TUM-Dev/NavigaTUM/security/advisories/GHSA-59hj-f48w-hjfm
Restart Required: Yes
Instructions:
1. Pull latest NavigaTUM repository. 2. Apply commit 86f34c7. 3. Restart the application server.
🔧 Temporary Workarounds
Disable propose_edits endpoint
allTemporarily disable the vulnerable endpoint until patching.
Modify application configuration to block access to /propose_edits
Restrict file write permissions
linuxRemove write permissions from application user on sensitive directories.
chmod -R a-w /path/to/cdn
chmod -R a-w /path/to/other/writable/dirs
🧯 If You Can't Patch
- Implement web application firewall (WAF) rules to block path traversal patterns in JSON payloads.
- Monitor file system changes in writable directories and alert on unexpected modifications.
🔍 How to Verify
Check if Vulnerable:
Check if commit 86f34c7 is applied: git log --oneline | grep 86f34c7Check Version:
git rev-parse HEADVerify Fix Applied:
Test propose_edits endpoint with traversal payloads; should reject or sanitize input.📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /propose_edits with JSON containing ../ sequences
- File write operations outside expected temporary directories
Network Indicators:
- Unusual POST payload sizes to propose_edits endpoint
- Multiple rapid requests to the same endpoint
SIEM Query:
source="web_logs" AND uri_path="/propose_edits" AND request_body MATCHES ".*\\.\\./.*"