CVE-2026-6530: Wireshark DCP-ETSI DoS Vulnerability

CVE-2026-6530 Overview

CVE-2026-6530 is a Heap Overflow vulnerability in the DCP-ETSI protocol dissector within Wireshark versions 4.6.0 to 4.6.4 and 4.4.0 to 4.4.14. This vulnerability allows an attacker to cause a denial of service condition by triggering a crash in the affected application when processing specially crafted network traffic or capture files containing malformed DCP-ETSI protocol data.

Critical Impact

Successful exploitation allows an attacker to crash Wireshark instances, disrupting network analysis operations and potentially causing loss of captured data during forensic investigations.

Affected Products

• Wireshark 4.6.0 to 4.6.4
• Wireshark 4.4.0 to 4.4.14

Discovery Timeline

• 2026-04-30 - CVE CVE-2026-6530 published to NVD
• 2026-04-30 - Last updated in NVD database

Technical Details for CVE-2026-6530

Vulnerability Analysis

This vulnerability is classified as CWE-122 (Heap-based Buffer Overflow), which occurs when data is written beyond the allocated boundaries of a heap buffer. In the context of the DCP-ETSI protocol dissector, the vulnerability manifests when Wireshark parses maliciously crafted or malformed DCP-ETSI protocol packets.

The DCP-ETSI (Digital Content Protection - European Telecommunications Standards Institute) dissector is responsible for parsing network traffic that conforms to the DCP-ETSI protocol specifications. When processing certain input, the dissector fails to properly validate buffer boundaries, leading to a heap overflow condition that results in an application crash.

The local attack vector requires user interaction, meaning an attacker would need to convince a user to open a malicious capture file or capture traffic containing the exploit payload on a network segment the attacker controls.

Root Cause

The root cause is a heap-based buffer overflow (CWE-122) in the DCP-ETSI protocol dissector. The dissector does not adequately validate the size of input data before writing it to a heap-allocated buffer, allowing malformed protocol data to trigger memory corruption. This lack of bounds checking results in an out-of-bounds write that corrupts heap memory and causes the application to crash.

Attack Vector

The attack requires local access and user interaction. An attacker can exploit this vulnerability through two primary methods:

1. Malicious Capture File: The attacker crafts a .pcap or .pcapng file containing malformed DCP-ETSI protocol data and distributes it to the victim. When the victim opens the file in Wireshark, the vulnerable dissector processes the malicious packet and crashes.

2. Live Capture Scenario: If the attacker has access to the same network segment as the victim, they can inject malformed DCP-ETSI protocol packets that will be captured by Wireshark, triggering the crash during live analysis.

The vulnerability causes a denial of service condition by crashing Wireshark, which can disrupt ongoing forensic investigations or network troubleshooting sessions. For more technical details, refer to the Wireshark Security Advisory 2026-31 and the GitLab Wireshark Work Item.

Detection Methods for CVE-2026-6530

Indicators of Compromise

• Unexpected Wireshark crashes when opening specific capture files or analyzing network traffic
• Error logs indicating segmentation faults or access violations in the DCP-ETSI dissector component
• Presence of .pcap or .pcapng files containing anomalous DCP-ETSI protocol frames

Detection Strategies

• Monitor application crash logs for Wireshark instances, particularly crashes occurring during packet dissection
• Implement file integrity monitoring for capture files before analysis to detect potentially malicious content
• Use sandboxed environments for analyzing untrusted capture files to contain potential exploitation attempts

Monitoring Recommendations

• Track Wireshark version deployments across the organization to identify vulnerable installations
• Implement alerting for repeated Wireshark crashes that may indicate exploitation attempts
• Review network traffic for unusual DCP-ETSI protocol activity that could be used as an attack vector

How to Mitigate CVE-2026-6530

Immediate Actions Required

• Update Wireshark to a patched version beyond 4.6.4 (for the 4.6.x branch) or 4.4.14 (for the 4.4.x branch)
• Disable the DCP-ETSI protocol dissector if not required for analysis tasks until patches can be applied
• Avoid opening capture files from untrusted or unknown sources
• Use TShark or other command-line tools with limited dissector scope when processing untrusted capture files

Patch Information

The Wireshark development team has addressed this vulnerability in subsequent releases. Users should upgrade to the latest stable version available from the official Wireshark website. For detailed patch information and affected versions, consult the Wireshark Security Advisory 2026-31.

Workarounds

• Disable the DCP-ETSI dissector by navigating to Analyze > Enabled Protocols and unchecking DCP-ETSI
• Use capture filters to exclude DCP-ETSI traffic if the protocol is not needed for analysis
• Process untrusted capture files in isolated virtual machines or containers to limit the impact of potential crashes
• Apply network segmentation to prevent attackers from injecting malicious traffic into monitored network segments

# Disable DCP-ETSI dissector via command line
wireshark --disable-protocol dcp-etsi
# Or use TShark with specific protocol filtering
tshark -r capture.pcap --disable-protocol dcp-etsi