CVE-2026-6523
Description
A flaw was found in the GNW protocol dissector in Wireshark. This issue occurs when malformed packets are decoded from a pcap file or the network, causing an infinite loop that leads to an excessive consumption of CPU resources, resulting in a denial of service.
Statement
This issue will cause a crash in Wireshark with no other security impact. Also, this flaw can only be exploited when a malformed pcap file is processed. Due to these reasons, this vulnerability has been rated with a moderate severity.
Mitigation
If the GNW protocol dissector is not being used, it can be disabled via the "Enabled Protocols" dialog box in the Wireshark GUI application. This will also disable the protocol dissector when using "tshark", the command line tool.
See the links below for instructions to disable a protocol in Wireshark, specifically the "Control Protocol Dissection" section and the "disabled_protos" configuration file option.
https://www.wireshark.org/docs/wsug_html_chunked/ChCustProtocolDissectionSection.html
https://www.wireshark.org/docs/wsug_html_chunked/ChAppFilesConfigurationSection.html
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.5 | N/A | 5.5 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Amplification
An infinite loop will cause unexpected consumption of resources, such as CPU cycles or memory. The software's operation may slow down, or cause a long time to respond.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
