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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-40170 Detail

Description

ngtcp2 is a C implementation of the IETF QUIC protocol. In versions prior to 1.22.1, ngtcp2_qlog_parameters_set_transport_params() serializes peer transport parameters into a fixed 1024-byte stack buffer without bounds checking. When qlog is enabled, a remote peer can send sufficiently large transport parameters during the QUIC handshake to cause writes beyond the buffer boundary, resulting in a stack buffer overflow. This affects deployments that enable the qlog callback and process untrusted peer transport parameters. This issue has been fixed in version 1.22.1. If developers are unable to immediately upgrade, they can disable the qlog on client.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
http://www.openwall.com/lists/oss-security/2026/04/17/12 CVE
https://github.com/ngtcp2/ngtcp2/commit/708a7640c1f48fb8ffb540c4b8ea5b4c1dfb8ee5 GitHub, Inc.
https://github.com/ngtcp2/ngtcp2/security/advisories/GHSA-f523-465f-8c8f GitHub, Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-121 Stack-based Buffer Overflow GitHub, Inc.  

Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-40170
NVD Published Date:
04/16/2026
NVD Last Modified:
04/17/2026
Source:
GitHub, Inc.