CVEvulnerability

CVE-2026-40170

7.5 HIGH Published 2026-04-16 Modified 2026-07-15 Official page ↗
Status
Modified
Published
2026-04-16
Last modified
2026-07-15
Assigner
[email protected]
CVSS 3.1 ([email protected])
7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 3.1 (0b0ca135-0b70-47e7-9f44-1890c2a1c46c)
7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weaknesses
CWE-120, CWE-121

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.

Affected configurations

• tatsuhiro-t ngtcp2 (< 1.22.1)

Related

Weakness · CWE (2)

  • CWE-120 Buffer Copy without Checking Size of Input weakness
  • CWE-121 Stack-based Buffer Overflow weakness

References