CVE-2026-6328
Improper Signature Verification in XQUIC Enables Protocol Manipulation
Publication date: 2026-04-15
Last updated on: 2026-04-15
Assigner: Alibaba, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| xquic_project | xquic | to 1.8.3 (inc) |
| alibaba | xquic | 1.8.3 |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-20 | The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. |
| CWE-347 | The product does not verify, or incorrectly verifies, the cryptographic signature for data. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability in the XQUIC project involves improper input validation and improper verification of cryptographic signatures within the QUIC protocol implementation, specifically in the packet processing and STREAM frame handler modules. The issue allows protocol manipulation by permitting illegal STREAM frames to appear in INIT and HSK (handshake) packets, which violates protocol specifications.
The vulnerability arises because the software did not correctly detect and reject STREAM frames in these packet types. The fix adds checks to detect such illegal frames, logs an error, closes the connection with a protocol violation error, and prevents further processing of the illegal frame.
How can this vulnerability impact me? :
This vulnerability can impact you by allowing an attacker to manipulate the QUIC protocol communication. By sending illegal STREAM frames in INIT or HSK packets, an attacker could cause protocol violations that may disrupt normal communication, potentially leading to connection termination or denial of service.
Such protocol manipulation could undermine the reliability and security of the network communication relying on XQUIC, possibly affecting applications that depend on it for secure and stable data transmission.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability involves illegal STREAM frames appearing in INIT or HSK packets, which violates the QUIC protocol specifications.
Detection can be performed by monitoring network traffic for QUIC packets and inspecting the packet types and frame contents to identify STREAM frames within INIT or HSK packets.
Specifically, you can use packet capture tools like tcpdump or Wireshark to capture QUIC traffic and then filter or analyze packets for protocol violations.
- Use tcpdump to capture QUIC traffic: tcpdump -i <interface> udp port <quic_port> -w capture.pcap
- Open the capture in Wireshark and filter for QUIC INIT or HSK packets containing STREAM frames.
- Alternatively, use custom scripts or tools that parse QUIC packets to detect STREAM frames in INIT or HSK packets, which indicate the vulnerability.
What immediate steps should I take to mitigate this vulnerability?
Immediate mitigation involves updating the XQUIC implementation to a version that includes the patch fixing this vulnerability.
The patch adds checks in the function handling STREAM frames to reject illegal STREAM frames in INIT and HSK packets, closing connections that violate protocol rules.
If updating is not immediately possible, consider monitoring and blocking QUIC packets that contain STREAM frames in INIT or HSK packets at the network perimeter to prevent exploitation.
- Apply the patch from the official repository or upgrade to a fixed version beyond 1.8.3.
- Implement network-level filtering or intrusion detection rules to detect and block protocol violations.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The provided information does not specify how this vulnerability impacts compliance with common standards and regulations such as GDPR or HIPAA.