CVE-2025-26819
📋 TL;DR
Monero versions before commit ec74ff4 lack HTTP server connection response limits, allowing attackers to exhaust server resources through unlimited response sizes. This affects all Monero nodes running vulnerable versions with HTTP RPC enabled. The vulnerability enables denial-of-service attacks against Monero network infrastructure.
💻 Affected Systems
- Monero
📦 What is this software?
Monero by Getmonero
⚠️ Risk & Real-World Impact
Worst Case
Complete resource exhaustion leading to node crash, service disruption, and potential cascading failures in the Monero network if multiple nodes are targeted simultaneously.
Likely Case
Degraded node performance, increased latency, and temporary service unavailability for the affected node and its connected peers.
If Mitigated
Minimal impact with proper network segmentation, rate limiting, and monitoring in place to detect and block excessive requests.
🎯 Exploit Status
Attack requires network access to the HTTP RPC port but no authentication. Simple HTTP requests can trigger the vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Monero commit ec74ff4a3d3ca38b7912af680209a45fd1701c3d and later
Vendor Advisory: https://github.com/monero-project/monero/commit/ec74ff4a3d3ca38b7912af680209a45fd1701c3d
Restart Required: Yes
Instructions:
1. Update Monero to latest version or apply commit ec74ff4. 2. Restart the Monero daemon. 3. Verify the fix by checking version or testing response limits.
🔧 Temporary Workarounds
Disable HTTP RPC
allDisable the HTTP RPC interface if not required for node operation.
Edit monerod configuration to set --rpc-bind-ip to localhost only or disable entirely
Network Segmentation
LinuxRestrict access to Monero HTTP RPC port using firewall rules.
iptables -A INPUT -p tcp --dport 18081 -j DROP (adjust port as needed)
🧯 If You Can't Patch
- Implement strict network access controls to limit HTTP RPC access to trusted sources only.
- Deploy rate limiting and connection monitoring at network perimeter to detect and block excessive requests.
🔍 How to Verify
Check if Vulnerable:
Check Monero version: if before commit ec74ff4 and HTTP RPC is enabled, system is vulnerable.Check Version:
monerod --versionVerify Fix Applied:
Verify Monero version includes commit ec74ff4 or test with controlled HTTP requests to confirm response limits.📡 Detection & Monitoring
Log Indicators:
- Unusually large HTTP responses
- High memory/CPU usage spikes
- Connection timeouts
Network Indicators:
- Excessive HTTP traffic to Monero RPC port
- Large response packets from Monero node
SIEM Query:
source="monerod.log" AND ("HTTP response" AND size>1000000) OR ("memory exhaustion" OR "connection limit")