# CVE-2026-96421: Wireshark USB HID dissector infinite loop in Usage range parsing

Source: https://junglewise.ai/threats/cve-2026-96421-usb-hid-protocol-dissector-infinite-loop-and-memory-leak-in-4-6-0  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-29. Updated: 2026-09-29  
License: CC BY 4.0 with a link back

CVE-2026-96421 · Severity: medium · CVSS 5.5 · Published 2026-09-29

Wireshark's USB packet analyzer contains a flaw in how it parses USB device descriptor files that could cause the application to hang indefinitely and consume all available memory. An attacker can craft a malicious USB capture file that, when opened in Wireshark, will freeze the program and exhaust system resources, causing a denial of service. No data is exposed or modified by this vulnerability.

Technologies: [Wireshark](https://junglewise.ai/threats/technologies/wireshark). Vendors: [Wireshark](https://junglewise.ai/threats/vendors/wireshark).

## Quick answers

**Is CVE-2026-96421 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-96421 being exploited in the wild.

**How severe is CVE-2026-96421?** Medium severity, with a CVSS score of 5.5, published 29 September 2026.

**Which products and versions are affected?** Wireshark 4.4.0 to 4.4.18, 4.6.0 to 4.6.8.

**Is there a fix for CVE-2026-96421?** A patch was published on 2026: Fixed in versions 4.6.9 and 4.4.19 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-96421 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-96421?** Check whether you run Wireshark at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The USB HID dissector's parse_report_descriptor() function uses an unchecked uint32_t loop counter when expanding Usage Minimum/Maximum ranges. When usage_max is 0xFFFFFFFF, the loop counter wraps from 0xFFFFFFFF to 0 on the next increment, creating an infinite loop that continuously appends to an unbounded wmem array. The existing bounds check (MAX_REPORT_DESCRIPTOR_COUNT) only validates the declared range delta, not the absolute wraparound, allowing malformed descriptors with usage_min=0xFFFFFFFE and usage_max=0xFFFFFFFF to bypass all protections.

## Affected products

- Wireshark Wireshark 4.4.0 to 4.4.18, 4.6.0 to 4.6.8

## Timeline

- 2026-09-23: disclosed
- 2026: patched: Fixed in versions 4.6.9 and 4.4.19

## References

- [https://gitlab.com/wireshark/wireshark/-/work_items/21566](https://gitlab.com/wireshark/wireshark/-/work_items/21566)
- [https://www.wireshark.org/security/wnpa-sec-2026-103.html](https://www.wireshark.org/security/wnpa-sec-2026-103.html)

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