CVE-2026-6534
USB HID Protocol Infinite Loop in Wireshark
Publication date: 2026-04-30
Last updated on: 2026-05-01
Assigner: GitLab Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| wireshark | wireshark | From 4.4.0 (inc) to 4.4.14 (inc) |
| wireshark | wireshark | From 4.6.0 (inc) to 4.6.4 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-835 | The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in the USB HID protocol dissector of Wireshark versions 4.6.0 to 4.6.4 and 4.4.0 to 4.4.14. It is caused by improper validation of the REPORT_COUNT value in a HID report descriptor. Specifically, when REPORT_SIZE is set to 0 and REPORT_COUNT is set to a very large value (e.g., 0xFFFFFFFF), the dissector enters an effectively infinite loop.
During this loop, the bit offset does not advance and bounds checks are not triggered, causing billions of iterations. Each iteration allocates memory for proto_tree, leading to extreme CPU usage and eventually causing the application to run out of memory and terminate.
The root cause is the lack of an upper bound check on the REPORT_COUNT value, allowing an attacker to craft a malicious descriptor that crashes Wireshark during packet dissection.
How can this vulnerability impact me? :
This vulnerability can cause a denial of service (DoS) condition in Wireshark by exhausting CPU and memory resources. An attacker can exploit this by sending or providing a malicious USB HID report descriptor that triggers an infinite loop in the dissector.
The impact is that Wireshark will crash or become unresponsive during packet analysis, potentially disrupting network troubleshooting or forensic activities.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability occurs when Wireshark processes a malicious USB HID report descriptor with REPORT_SIZE set to 0 and a very large REPORT_COUNT value, causing an infinite loop and CPU exhaustion.
Detection involves monitoring Wireshark's behavior for unusually high CPU usage or crashes during packet dissection of USB HID traffic.
A practical approach is to analyze USB HID traffic captures (pcap files) for descriptors with REPORT_SIZE=0 and abnormally large REPORT_COUNT values.
While no specific commands are provided in the resources, you can use Wireshark filters to isolate USB HID traffic and inspect the report descriptors manually.
What immediate steps should I take to mitigate this vulnerability?
The immediate mitigation is to upgrade Wireshark to a fixed version: 4.6.5 or later, or 4.4.15 or later.
Until upgrading, avoid opening or dissecting untrusted USB HID traffic captures that may contain malicious descriptors.
Monitoring and limiting access to Wireshark usage on sensitive systems can also reduce exposure.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The provided information does not specify any direct impact of this vulnerability on compliance with common standards and regulations such as GDPR or HIPAA.