CVE-2026-0601
📋 TL;DR
This reflected cross-site scripting vulnerability in Nexus Repository 3 allows unauthenticated attackers to execute malicious JavaScript in users' browsers by tricking them into clicking specially crafted links. All organizations running vulnerable versions of Nexus Repository 3 are affected, particularly those with internet-facing instances.
💻 Affected Systems
- Sonatype Nexus Repository 3
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal session cookies, perform actions as authenticated users, redirect to malicious sites, or install malware on victim systems.
Likely Case
Session hijacking leading to unauthorized access to the repository, potential data theft, or privilege escalation within the Nexus environment.
If Mitigated
Limited impact with proper input validation and output encoding, though user interaction is still required for exploitation.
🎯 Exploit Status
Exploitation requires social engineering to get users to click malicious links. No authentication is required to trigger the vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.88.0
Vendor Advisory: https://help.sonatype.com/en/sonatype-nexus-repository-3-88-0-release-notes.html
Restart Required: Yes
Instructions:
1. Backup your Nexus Repository configuration and data. 2. Download Nexus Repository 3.88.0 or later from Sonatype. 3. Stop the Nexus service. 4. Install the new version following Sonatype's upgrade guide. 5. Start the Nexus service. 6. Verify the version is 3.88.0 or higher.
🔧 Temporary Workarounds
Input Validation Filter
allImplement a web application firewall or reverse proxy with XSS filtering rules to sanitize malicious input before it reaches Nexus.
Content Security Policy
allImplement strict Content-Security-Policy headers to limit script execution sources and reduce XSS impact.
🧯 If You Can't Patch
- Restrict Nexus Repository access to internal networks only using firewall rules.
- Implement user awareness training about phishing and suspicious links, and use browser security extensions that block reflected XSS.
🔍 How to Verify
Check if Vulnerable:
Check the Nexus Repository version in the web interface under Administration → System Information, or run: cat /opt/sonatype/nexus/etc/nexus-default.properties | grep nexus-versionCheck Version:
cat /opt/sonatype/nexus/etc/nexus-default.properties | grep nexus-versionVerify Fix Applied:
Confirm the version is 3.88.0 or higher using the same methods, and test that reflected XSS payloads no longer execute.📡 Detection & Monitoring
Log Indicators:
- Unusual GET requests with JavaScript payloads in query parameters
- Multiple 400/404 errors with suspicious parameter values
Network Indicators:
- HTTP requests containing script tags or JavaScript code in URL parameters
- Traffic patterns showing users accessing Nexus via unusual referral URLs
SIEM Query:
source="nexus.log" AND ("<script" OR "javascript:" OR "onerror=" OR "onload=") AND status=200