CVE-2026-6531
SANE Protocol Dissector Infinite Loop in Wireshark
Publication date: 2026-04-30
Last updated on: 2026-05-01
Assigner: GitLab Inc.
Description
Description
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
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 is an infinite loop in the SANE protocol dissector component of Wireshark versions 4.6.0 to 4.6.4 and 4.4.0 to 4.4.14.
Specifically, the dissect_control_option_value() function contains an unbounded loop that occurs when the value_type field is set to an unrecognized value. Because the loop lacks handling for unknown value types, it can iterate up to approximately 2^31 times without doing any meaningful work.
This causes Wireshark or tshark to hang indefinitely, consuming 100% CPU and eventually crashing.
The vulnerability can be triggered by a single specially crafted 119-byte Ethernet frame, particularly a TCP packet sent to or from port 6566 with specific opcode values related to the SANE protocol.
How can this vulnerability impact me? :
This vulnerability can cause a denial of service (DoS) condition by making Wireshark or tshark hang indefinitely and consume 100% CPU.
As a result, network analysis or monitoring activities relying on Wireshark could be disrupted, potentially delaying troubleshooting or security investigations.
Since the issue can be triggered remotely by a crafted network packet, an attacker could exploit this to disrupt your network monitoring tools without needing local access.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability can be detected by monitoring for TCP packets sent to or from port 6566 that contain the SANE_NET_CONTROL_OPTION opcode (opcode 5). Specifically, a crafted 119-byte Ethernet frame with this opcode can trigger the issue.
Detection can involve capturing and analyzing network traffic for suspicious packets targeting port 6566 with opcode 5, which is related to the SANE protocol.
Additionally, observing Wireshark or tshark processes for high CPU usage or hanging behavior when processing such packets can indicate exploitation attempts.
- Use tcpdump or tshark to capture packets on port 6566: tcpdump -i <interface> tcp port 6566 -w capture.pcap
- Analyze captured packets with Wireshark or tshark to look for SANE_NET_CONTROL_OPTION (opcode 5) packets.
- Monitor Wireshark or tshark CPU usage for spikes or hangs when processing SANE protocol traffic.
What immediate steps should I take to mitigate this vulnerability?
The immediate mitigation step is to upgrade Wireshark to a fixed version where this vulnerability is resolved.
- Upgrade Wireshark to version 4.6.5 or later, or 4.4.15 or later, as these versions contain the fix for the infinite loop issue.
Until the upgrade can be applied, avoid analyzing or capturing SANE protocol traffic on port 6566 to prevent triggering the vulnerability.
- Block or filter TCP traffic on port 6566 at network boundaries if SANE protocol analysis is not required.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The provided information does not specify any impact of this vulnerability on compliance with common standards and regulations such as GDPR or HIPAA.