CVE-2026-6525 Overview
CVE-2026-6525 is a denial-of-service vulnerability in the IEEE 802.11 protocol dissector of Wireshark versions 4.6.0 through 4.6.4. A malformed 802.11 frame processed by the dissector triggers a null pointer dereference, crashing the Wireshark process. The flaw is tracked under CWE-476 and documented in Wireshark Security Advisory WNPA-SEC-2026-36. Exploitation requires a local user to open a crafted capture file or feed a malicious packet stream into the dissector. The issue affects analyst workstations performing wireless protocol analysis and packet inspection workflows.
Critical Impact
An attacker who convinces an analyst to open a malicious .pcap or .pcapng capture file can crash Wireshark and disrupt incident response or network forensics activities.
Affected Products
- Wireshark 4.6.0
- Wireshark 4.6.1 through 4.6.3
- Wireshark 4.6.4
Discovery Timeline
- 2026-05-02 - CVE-2026-6525 published to the National Vulnerability Database
- 2026-05-05 - Last updated in NVD database
Technical Details for CVE-2026-6525
Vulnerability Analysis
The vulnerability resides in the IEEE 802.11 wireless protocol dissector that Wireshark uses to decode Wi-Fi frames. When the dissector processes a specially crafted 802.11 frame, it dereferences a pointer that has not been initialized or validated. The result is an immediate crash of the Wireshark application or the tshark command-line analyzer. The flaw maps to CWE-476: NULL Pointer Dereference. Impact is limited to availability — confidentiality and integrity are not affected. Analysts lose access to in-progress capture sessions and any unsaved annotations when the process terminates.
Root Cause
The root cause is missing validation of an internal data structure during 802.11 frame parsing. The dissector assumes a field or sub-structure is populated before reading it, but a malformed frame leaves the pointer null. Refer to the Wireshark GitLab work item 21008 for code-level details from the maintainers.
Attack Vector
Exploitation requires local user interaction. An attacker delivers a malicious capture file to a target analyst through email, shared storage, or a forensic ticket attachment. When the analyst opens the file in Wireshark, the dissector parses the embedded 802.11 frames and crashes. Live capture interfaces can also trigger the bug if a nearby attacker injects malformed frames into a monitored wireless segment.
No verified proof-of-concept code is publicly available. See the Wireshark Security Advisory WNPA-SEC-2026-36 for technical details published by the vendor.
Detection Methods for CVE-2026-6525
Indicators of Compromise
- Unexpected crashes of wireshark.exe, tshark, or dumpcap processes on analyst workstations during 802.11 capture analysis
- Capture files received from untrusted sources containing malformed IEEE 802.11 management or control frames
- Application error logs referencing the packet-ieee80211 dissector module at the time of crash
Detection Strategies
- Monitor endpoint telemetry for repeated abnormal terminations of Wireshark processes, particularly with non-zero exit codes following capture file open events
- Inspect inbound .pcap and .pcapng files in mail and file-sharing gateways for 802.11 frames with anomalous header structures
- Correlate file-open events with subsequent process crashes to identify weaponized capture files distributed to forensic staff
Monitoring Recommendations
- Track installed Wireshark versions across analyst endpoints and flag any instance running 4.6.0 through 4.6.4
- Alert on capture files arriving from external senders that target users in security operations or network engineering groups
- Review crash dump artifacts on workstations to confirm whether the 802.11 dissector is the failing module
How to Mitigate CVE-2026-6525
Immediate Actions Required
- Upgrade Wireshark to a fixed release as identified in WNPA-SEC-2026-36
- Instruct analysts to avoid opening capture files received from untrusted or unverified sources until patching is complete
- Inventory all systems with Wireshark 4.6.0 through 4.6.4 installed, including portable and forensic toolkit deployments
Patch Information
The Wireshark Foundation has addressed the issue in updated 4.6.x releases. Consult the Wireshark Security Advisory WNPA-SEC-2026-36 and the GitLab work item 21008 for the fixed version and commit references. Apply the update across analyst workstations, jump hosts, and any automated pipelines that invoke tshark for 802.11 traffic processing.
Workarounds
- Disable the IEEE 802.11 dissector in Analyze > Enabled Protocols when handling untrusted captures and version upgrade is not yet possible
- Process suspect captures inside an isolated virtual machine or sandboxed analysis host to contain crashes and any follow-on impact
- Use editcap to strip 802.11 frames from a capture before opening it in the GUI when only higher-layer protocols are needed
# Verify installed Wireshark version on Linux endpoints
wireshark --version | head -n 1
# Disable the IEEE 802.11 dissector via tshark for batch processing
tshark -r suspect.pcapng --disable-protocol wlan -Y "not wlan" -w cleaned.pcapng
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
