CVE-2026-21484
📋 TL;DR
This vulnerability in AnythingLLM allows attackers to determine whether specific usernames exist in the system by observing different error messages from the password recovery endpoint. This enables username enumeration attacks, which can facilitate credential stuffing or targeted attacks. Anyone running vulnerable versions of AnythingLLM is affected.
💻 Affected Systems
- AnythingLLM
📦 What is this software?
Anythingllm by Mintplexlabs
⚠️ Risk & Real-World Impact
Worst Case
Attackers build a complete list of valid usernames, then conduct targeted password attacks or social engineering against identified users, potentially leading to account compromise.
Likely Case
Attackers enumerate some valid usernames and use them for credential stuffing attacks or to gather intelligence about the user base.
If Mitigated
With proper rate limiting and monitoring, enumeration attempts are detected and blocked before significant damage occurs.
🎯 Exploit Status
Simple HTTP requests to password recovery endpoint with different usernames can reveal existence through response differences.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Commit e287fab56089cf8fcea9ba579a3ecdeca0daa313
Vendor Advisory: https://github.com/Mintplex-Labs/anything-llm/security/advisories/GHSA-47vr-w3vm-69ch
Restart Required: Yes
Instructions:
1. Update to commit e287fab56089cf8fcea9ba579a3ecdeca0daa313 or later. 2. Restart the AnythingLLM service. 3. Verify the fix by testing password recovery responses.
🔧 Temporary Workarounds
Rate Limit Password Recovery
allImplement rate limiting on the password recovery endpoint to slow enumeration attempts.
# Configure rate limiting in your web server or application firewall
Disable Password Recovery
allTemporarily disable the password recovery functionality if not essential.
# Modify application configuration to disable password recovery endpoint
🧯 If You Can't Patch
- Implement web application firewall rules to detect and block username enumeration patterns
- Monitor authentication logs for unusual patterns of password recovery attempts
🔍 How to Verify
Check if Vulnerable:
Send password recovery requests with valid and invalid usernames. If responses differ (e.g., different error messages or timing), the system is vulnerable.Check Version:
Check git commit hash or version in application interfaceVerify Fix Applied:
After patching, test password recovery with both valid and invalid usernames. Responses should be identical in format and timing.📡 Detection & Monitoring
Log Indicators:
- Multiple failed password recovery attempts for different usernames
- Patterns of sequential username attempts
Network Indicators:
- High volume of POST requests to password recovery endpoint
- Requests with common username lists
SIEM Query:
source="web_logs" AND uri="/api/password-recovery" AND count by src_ip > 10 within 1h