> CVE-2026-40170 [HIGH]

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PUBLISHED
2026-04-16 22:16
MODIFIED
2026-04-16 22:16
CVSS_SCORE V3
7.5
EPSS (Prob. Exploit)
0.96%
Top 38.9%
DATA SOURCES:
NVD 🔗 2026-04-16 RED HAT 🔗 2026-04-19 CWE MITRE 🔗 2026-11-01 FIRST EPSS 🔗 2026-10-25 OSV 🔗 2026-07-26 MSRC 🔗 2026-07-01

> 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_PRODUCTS

ℹ️ Aucun produit affecté n'a encore été publié par NVD pour cette CVE.

> CVSS V3 METRICS

CVSS_VECTOR
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EXPLOITABILITY
3.9
IMPACT
3.6

> MÉTRIQUES CVSS DÉTAILLÉES

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Métrique Valeur Interprétation
AV (Vecteur d'Attaque)
Attack Vector
Network (N)
Exploit possible à distance via réseau (HTTP, API, etc.)
AC (Complexité d'Attaque)
Attack Complexity
Low (L)
Peu de conditions requises pour exploiter
PR (Privilèges Requis)
Privileges Required
None (N)
Aucune authentification requise
UI (Interaction Utilisateur)
User Interaction
None (N)
Aucune interaction utilisateur nécessaire
S (Périmètre)
Scope
Unchanged (U)
Impact reste dans le périmètre du composant compromis
C (Impact Confidentialité)
Confidentiality Impact
None (N)
Aucune divulgation d'informations
I (Impact Intégrité)
Integrity Impact
None (N)
Aucune modification de données possible
A (Impact Disponibilité)
Availability Impact
High (H)
Interruption totale du service possible

> RÉSUMÉ DES IMPACTS

Confidentialité
None
Aucune divulgation d'informations
Intégrité
None
Aucune modification de données possible
Disponibilité
High
Interruption totale du service possible

> WEAKNESSES

CWE-121

> CWE DETAILED DESCRIPTIONS

CWE-121: Stack-based Buffer Overflow - The product writes past the end of a buffer that was allocated on the stack.

> RED HAT SECURITY ADVISORIES

Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update
An update for Red Hat Hardened Images RPMs is now available.
Red Hat Security Advisory: samba security update
An update for samba is now available for Red Hat Enterprise Linux 10. Red Hat Product Security has rated this update as having a security impact of Critical. A Common Vulnerability Scoring System (CV...
Red Hat Security Advisory: samba security update
An update for samba is now available for Red Hat Enterprise Linux 9. Red Hat Product Security has rated this update as having a security impact of Critical. A Common Vulnerability Scoring System (CVS...

> RED HAT SEVERITY ASSESSMENT

THREAT SEVERITY
Important

> OSV (GOOGLE OPEN SOURCE VULNERABILITIES)

ngtcp2 has a qlog transport parameter serialization stack buffer overflow

AFFECTED PACKAGES:
Unknown / Unknown
42 versions affected
ALIASES:
GHSA-f523-465f-8c8f

> HISTORIQUE DES MODIFICATIONS

Première apparition
16/04/2026 22:16
Source: NVD
📊 ENRICHISSEMENT 01/11/2026 06:59
CWE
Champ modifié: Description CWE
Ancienne valeur:
CWE-121: Stack-based Buffer Overflow - A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a para...
Nouvelle valeur:
CWE-121: Stack-based Buffer Overflow - The product writes past the end of a buffer that was allocated on the stack.
📊 ENRICHISSEMENT 01/05/2026 06:01
CWE
Champ modifié: Description CWE
Ancienne valeur:
N/A
Nouvelle valeur:
CWE-121: Stack-based Buffer Overflow - A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a para...
📊 ENRICHISSEMENT 19/04/2026 05:01
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
N/A
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 19/04/2026 05:01
REDHAT
Champ modifié: Red Hat
Ancienne valeur:
Non
Nouvelle valeur:
Oui
Total des modifications: 4 Dernière mise à jour: 1 week ago

> REFERENCES

https://github.com/ngtcp2/ngtcp2/commit/708a7640c1f48fb8ffb540c4b8ea5b4c1dfb8ee5
https://github.com/ngtcp2/ngtcp2/security/advisories/GHSA-f523-465f-8c8f
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