DEBIAN-CVE-2026-40170

Advisory lineage Upstream: 1 Downstream: 0
Upstream
CVE-2026-40170
Published: 16 Apr 2026, 22:16
Last modified:15 Jun 2026, 19:06

Vulnerability Summary

Overall Risk (default)
medium
30/100
CVSS Score
7.5 HIGH
3.1 (osv_debian)
EPSS Score
No data
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

16 Apr 2026, 22:16
Published
Vulnerability first disclosed
15 Jun 2026, 19:06
Last Modified
Vulnerability information updated

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.

CVSS Metrics

  • v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Systems

  • debian•ngtcp2

    all | all | all | < 0.12.1+dfsg-1+deb12u1 | < 1.11.0-1+deb13u1 | < 1.22.1-1

References (1)