CVE-2026-3203: Wireshark DOS Vulnerability

CVE-2026-3203 Overview

CVE-2026-3203 is an Out-of-Bounds Read vulnerability affecting the RF4CE Profile protocol dissector in Wireshark, the widely-used open-source network protocol analyzer. This vulnerability allows remote attackers to cause a denial of service by crafting malicious network packets that trigger a crash in the protocol dissector, disrupting network analysis operations and potentially causing loss of captured data.

Critical Impact

Remote attackers can crash Wireshark instances by sending specially crafted RF4CE Profile protocol packets, causing denial of service for network analysts and security operations teams relying on packet capture analysis.

Affected Products

• Wireshark 4.6.0 to 4.6.3
• Wireshark 4.4.0 to 4.4.13

Discovery Timeline

• 2026-02-25 - CVE-2026-3203 published to NVD
• 2026-02-26 - Last updated in NVD database

Technical Details for CVE-2026-3203

Vulnerability Analysis

This vulnerability stems from a buffer over-read condition (CWE-126) in the RF4CE Profile protocol dissector component of Wireshark. The RF4CE (Radio Frequency for Consumer Electronics) protocol is used for wireless communication in consumer electronics devices, and Wireshark includes a dissector to parse and display RF4CE traffic during packet analysis.

When processing malformed RF4CE Profile protocol frames, the dissector fails to properly validate the boundaries of the data being read, causing it to access memory beyond the allocated buffer. This out-of-bounds read operation results in a crash of the Wireshark application, effectively creating a denial of service condition.

The vulnerability is particularly concerning because it can be triggered remotely without any authentication. An attacker only needs to send malicious packets that will be captured and processed by a Wireshark instance analyzing network traffic. This makes it exploitable in scenarios where analysts are monitoring network segments that include attacker-controlled traffic.

Root Cause

The root cause is a buffer over-read vulnerability (CWE-126) in the RF4CE Profile protocol dissector. The dissector does not adequately validate input lengths before reading protocol field data, allowing malformed packets with incorrect length fields to cause memory reads beyond the intended buffer boundaries.

Attack Vector

The attack can be executed remotely over the network without requiring any privileges or user interaction. An attacker can craft malicious RF4CE Profile protocol packets and inject them into a network segment being monitored by Wireshark. When the vulnerable dissector processes these packets, it reads memory out of bounds, causing the application to crash. This attack vector is particularly effective against security operations centers and network monitoring teams who analyze live traffic captures.

The vulnerability mechanism involves crafted RF4CE Profile protocol frames with manipulated length fields that cause the dissector to read beyond buffer boundaries. Technical details are available in the GitLab Wireshark Issue and the Wireshark Security Advisory WNPA-2026-07.

Detection Methods for CVE-2026-3203

Indicators of Compromise

• Unexpected Wireshark crashes when processing capture files containing RF4CE protocol traffic
• Application crash logs showing faults in the RF4CE Profile dissector module
• Repeated restarts of Wireshark processes during live packet capture sessions
• System error reports indicating memory access violations in Wireshark

Detection Strategies

• Monitor for abnormal Wireshark process terminations, particularly during RF4CE traffic analysis
• Implement application crash monitoring and alerting for Wireshark instances in production environments
• Review capture files for unusually malformed RF4CE Profile protocol frames before analysis
• Deploy sandboxed or isolated analysis environments when processing untrusted packet captures

Monitoring Recommendations

• Enable application crash reporting and logging for all Wireshark deployments
• Monitor process stability metrics for packet analysis workstations
• Implement centralized logging for network analysis tools to detect patterns of exploitation attempts
• Consider using automated health checks for long-running Wireshark capture sessions

How to Mitigate CVE-2026-3203

Immediate Actions Required

• Update Wireshark to version 4.6.4 or later (for 4.6.x branch) or version 4.4.14 or later (for 4.4.x branch)
• Disable the RF4CE Profile protocol dissector if RF4CE traffic analysis is not required
• Avoid processing untrusted packet captures on production systems until patches are applied
• Consider using isolated virtual machines for analyzing potentially malicious capture files

Patch Information

Wireshark has released patched versions addressing this vulnerability. Users should upgrade to the latest stable releases as documented in the Wireshark Security Advisory WNPA-2026-07. The fix addresses the buffer over-read condition in the RF4CE Profile protocol dissector by implementing proper bounds checking before memory read operations.

Workarounds

• Disable the RF4CE Profile protocol dissector via Wireshark preferences (Analyze > Enabled Protocols > RF4CE Profile)
• Process potentially malicious captures in isolated environments or virtual machines
• Use tshark with protocol filtering to exclude RF4CE traffic when full GUI analysis is not required
• Implement network segmentation to prevent attacker-controlled traffic from reaching analysis systems

# Disable RF4CE Profile dissector in Wireshark preferences file
# Add the following to ~/.config/wireshark/disabled_protos
rf4ce_profile

# Alternatively, start Wireshark with the dissector disabled
wireshark --disable-protocol rf4ce_profile

# For tshark, exclude RF4CE traffic during capture analysis
tshark -r capture.pcap --disable-protocol rf4ce_profile