CVE-2026-5409 Overview
CVE-2026-5409 is a denial of service vulnerability affecting the Monero protocol dissector in Wireshark network analyzer versions 4.6.0 to 4.6.4 and 4.4.0 to 4.4.14. The vulnerability allows an attacker to crash the Wireshark application by providing maliciously crafted network traffic that triggers uncontrolled recursion in the Monero dissector component.
Critical Impact
Successful exploitation causes Wireshark to crash, disrupting network analysis operations and potentially causing loss of captured packet data during forensic investigations or network troubleshooting sessions.
Affected Products
- Wireshark 4.6.0 through 4.6.4
- Wireshark 4.4.0 through 4.4.14
Discovery Timeline
- 2026-04-30 - CVE CVE-2026-5409 published to NVD
- 2026-04-30 - Last updated in NVD database
Technical Details for CVE-2026-5409
Vulnerability Analysis
This vulnerability exists within Wireshark's Monero protocol dissector, a component responsible for parsing and analyzing Monero cryptocurrency network traffic. The underlying weakness is classified as CWE-674 (Uncontrolled Recursion), indicating that the dissector fails to properly limit recursive function calls when processing specially crafted Monero protocol packets.
When Wireshark attempts to dissect malformed Monero traffic, the recursive parsing logic can be triggered repeatedly without adequate termination conditions. This leads to stack exhaustion and ultimately causes the application to crash. The attack requires local access, meaning an attacker must convince a user to open a malicious capture file or the user must capture traffic containing the malicious packets on their network.
Root Cause
The root cause is uncontrolled recursion (CWE-674) in the Monero protocol dissector implementation. The dissector lacks proper bounds checking or recursion depth limits when parsing nested or malformed protocol structures, allowing crafted input to trigger excessive recursive calls that exhaust the call stack.
Attack Vector
The vulnerability has a local attack vector requiring user interaction. An attacker can exploit this vulnerability through two primary methods:
- Malicious Capture File: Crafting a pcap or pcapng file containing malicious Monero protocol packets and convincing a victim to open it in Wireshark
- Network Traffic Injection: Injecting malicious Monero protocol packets on a network segment being captured by the target Wireshark instance
The vulnerability manifests when the Monero dissector processes specially crafted packets that trigger recursive parsing without proper termination. For technical details, see the Wireshark Security Advisory WNPA-SEC-2026-08 and the GitLab Wireshark Issue #21066.
Detection Methods for CVE-2026-5409
Indicators of Compromise
- Wireshark process crashes when opening capture files containing Monero protocol traffic
- Unexpected termination of wireshark or tshark processes during packet analysis
- Crash dumps or core files generated by Wireshark with stack traces showing deep recursion in Monero dissector functions
Detection Strategies
- Monitor for abnormal Wireshark process terminations or crash events on analyst workstations
- Implement file integrity monitoring for capture files from untrusted sources before analysis
- Review system logs for repeated Wireshark crashes correlated with specific capture files
Monitoring Recommendations
- Configure endpoint detection solutions to alert on repeated Wireshark crashes
- Implement sandbox analysis for pcap files received from external sources
- Track Wireshark version deployments across the organization to identify vulnerable installations
How to Mitigate CVE-2026-5409
Immediate Actions Required
- Upgrade Wireshark to version 4.6.5 or later (for 4.6.x branch) or 4.4.15 or later (for 4.4.x branch)
- Avoid opening capture files from untrusted sources until patches are applied
- Consider disabling the Monero protocol dissector as a temporary workaround if Monero traffic analysis is not required
Patch Information
Security updates addressing this vulnerability are available from the Wireshark Foundation. Users should update to the latest stable release for their respective version branch. Refer to the Wireshark Security Advisory WNPA-SEC-2026-08 for official patch information.
Workarounds
- Disable the Monero protocol dissector via Wireshark preferences: Navigate to Analyze → Enabled Protocols and disable the Monero dissector
- Use tshark with the -d flag to explicitly exclude Monero dissection when processing untrusted captures
- Analyze suspicious capture files in an isolated virtual machine environment to contain potential crashes
# Disable Monero dissector via command line when analyzing captures
tshark -r capture.pcap --disable-protocol monero
# Alternative: Create a disabled protocols file
echo "monero" >> ~/.config/wireshark/disabled_protos
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
