CVE-2026-31812
Received Received - Intake
Denial of Service in Quinn QUIC via Malformed Transport Parameters

Publication date: 2026-03-10

Last updated on: 2026-03-10

Assigner: GitHub, Inc.

Description
Quinn is a pure-Rust, async-compatible implementation of the IETF QUIC transport protocol. Prior to 0.11.14, a remote, unauthenticated attacker can trigger a denial of service in applications using vulnerable quinn versions by sending a crafted QUIC Initial packet containing malformed quic_transport_parameters. In quinn-proto parsing logic, attacker-controlled varints are decoded with unwrap(), so truncated encodings cause Err(UnexpectedEnd) and panic. This is reachable over the network with a single packet and no prior trust or authentication. This vulnerability is fixed in 0.11.14.
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Meta Information
Published
2026-03-10
Last Modified
2026-03-10
Generated
2026-06-16
AI Q&A
2026-03-11
EPSS Evaluated
2026-06-15
NVD
CVE-2026-31812
EUVD
EUVD-2026-10908
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
quinn quinn to 0.11.14 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-248 An exception is thrown from a function, but it is not caught.
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Executive Summary

This vulnerability exists in Quinn, a Rust implementation of the IETF QUIC transport protocol. Before version 0.11.14, a remote attacker who is not authenticated can cause a denial of service by sending a specially crafted QUIC Initial packet with malformed transport parameters. The issue arises because the parsing logic uses unwrap() on attacker-controlled varints, which leads to a panic when truncated encodings are encountered. This panic causes the application to crash or become unavailable.

Impact Analysis

The vulnerability can lead to a denial of service (DoS) condition in applications using affected versions of Quinn. An attacker can remotely crash the application by sending a single malformed packet without needing any prior authentication or trust. This can result in service interruptions and unavailability.

Compliance Impact

I don't know

Detection Guidance

I don't know

Mitigation Strategies

To mitigate this vulnerability, you should upgrade the quinn library to version 0.11.14 or later, where the issue has been fixed.

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