CVE-2026-76888 in Wireshark
Summary
by MITRE • 08/20/2026
RDP protocol dissector crash in 4.6.0 to 4.6.7 and 4.4.0 to 4.4.18 allows denial of service
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Analysis
by VulDB Data Team • 08/20/2026
The Remote Desktop Protocol (RDP) implementation within the specified software versions contains a critical flaw that leads to application crashes when processing malformed network traffic, resulting in a severe denial of service condition for users relying on this tool for packet analysis and network monitoring. This vulnerability specifically affects Wireshark versions ranging from 4.6.0 through 4.6.7 and 4.4.0 through 4.4.18, where the internal dissector responsible for parsing RDP packets fails to adequately validate input data before attempting memory operations or structural access. When a user opens a capture file containing specially crafted malicious payloads or views live traffic with anomalous RDP frames, the application encounters an unexpected state that triggers a crash rather than gracefully handling the error. This behavior effectively neutralizes the utility of the software for security analysts who depend on it to investigate network anomalies, as the sudden termination prevents further inspection and potentially causes loss of unsaved work or disrupts ongoing monitoring activities in production environments where such tools are used for real-time threat detection.
From a technical perspective, this issue is classified under CWE-125, which denotes Out-of-Bounds Read, indicating that the dissector likely attempts to access memory locations beyond the allocated buffer boundaries defined by the packet structure. The root cause lies in insufficient bounds checking during the parsing of specific RDP fields or structures, allowing an attacker who can inject traffic into a monitored network segment to trigger this out-of-bounds condition. In some variations of such flaws, improper pointer arithmetic or lack of validation for length fields may also contribute to memory corruption events that manifest as crashes rather than arbitrary code execution in these particular versions. The vulnerability aligns with MITRE ATT&CK technique T1498, Network Denial of Service, specifically under the sub-technique of Resource Exhaustion via Application Crashes, demonstrating how a simple malformed packet can be leveraged to disrupt operational continuity without requiring authentication or complex exploitation chains beyond network access.
The impact extends beyond mere inconvenience for individual users; in enterprise security operations centers where Wireshark is deployed on critical infrastructure monitoring stations, such crashes can lead to gaps in visibility during active incidents. Analysts may miss crucial indicators of compromise if the tool becomes unstable while processing high volumes of mixed traffic that includes both legitimate and malicious RDP communications. Furthermore, because this vulnerability affects multiple minor versions across two different release branches, it suggests a systemic issue within the core parsing logic for RDP rather than an isolated regression in a single update cycle. This necessitates immediate attention to ensure continuity of network forensics capabilities during security investigations where deep packet inspection is required.
Mitigation strategies primarily involve upgrading to patched versions that address these memory safety violations by implementing rigorous input validation and bounds checking within the RDP dissector module. Organizations should prioritize applying vendor-released patches as soon as they become available, ensuring that all workstations running affected software are updated to eliminate the crash vector. In environments where immediate patching is not feasible due to change management constraints or compatibility concerns with other tools, network segmentation can be employed to isolate traffic containing RDP packets from sensitive monitoring segments until updates are deployed. Additionally, security teams should consider deploying intrusion detection systems that flag anomalous RDP packet structures for further analysis rather than relying solely on endpoint-based dissectors for initial triage of suspicious network activity. Regular review of capture files and automated sanitization scripts can also help reduce exposure by filtering out potentially malicious payloads before they reach the vulnerable application layer, thereby maintaining operational resilience against denial-of-service attempts targeting forensic tools.