> CVE-2026-55999 [HIGH]

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PUBLISHED
2026-07-08 09:16
MODIFIED
2026-07-08 09:16
CVSS_SCORE V3
8.5
EPSS (Prob. Exploit)
0.33%
Top 74.7%
DATA SOURCES:
NVD 🔗 2026-07-08 RED HAT 🔗 2026-07-12 CWE MITRE 🔗 2026-11-01 FIRST EPSS 🔗 2026-10-25 OSV 🔗 2026-07-15 MSRC 🔗 2026-08-01

> DESCRIPTION

Local attackers with a X connection able to provide PCX fonts to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a heap buffer overflow via SetFont due to missing glyph boundary checks.

> 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:H/PR:L/UI:N/S:C/C:H/I:H/A:H
EXPLOITABILITY
1.8
IMPACT
6.0

> MÉTRIQUES CVSS DÉTAILLÉES

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/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
High (H)
Conditions spécifiques doivent être réunies pour exploiter
PR (Privilèges Requis)
Privileges Required
Low (L)
Authentifié avec compte utilisateur basique
UI (Interaction Utilisateur)
User Interaction
None (N)
Aucune interaction utilisateur nécessaire
S (Périmètre)
Scope
Changed (C)
Impact s'étend au-delà du composant compromis
C (Impact Confidentialité)
Confidentiality Impact
High (H)
Divulgation totale d'informations
I (Impact Intégrité)
Integrity Impact
High (H)
Modification totale des données possible
A (Impact Disponibilité)
Availability Impact
High (H)
Interruption totale du service possible

> RÉSUMÉ DES IMPACTS

Confidentialité
High
Divulgation totale d'informations
Intégrité
High
Modification totale des données possible
Disponibilité
High
Interruption totale du service possible

> WEAKNESSES

CWE-122

> CWE DETAILED DESCRIPTIONS

CWE-122: Heap-based Buffer Overflow - The product writes past the end of a buffer that was allocated on the heap.

> RED HAT SECURITY ADVISORIES

Red Hat Security Advisory: xorg-x11-server security update
An update for xorg-x11-server is now available for Red Hat Enterprise Linux 8. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring...
Red Hat Security Advisory: xorg-x11-server-Xwayland security update
An update for xorg-x11-server-Xwayland is now available for Red Hat Enterprise Linux 10. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerabilit...
Red Hat Security Advisory: xorg-x11-server-Xwayland security update
An update for xorg-x11-server-Xwayland is now available for Red Hat Enterprise Linux 8. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability...
Red Hat Security Advisory: xorg-x11-server security update
An update for xorg-x11-server is now available for Red Hat Enterprise Linux 9. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring...
Red Hat Security Advisory: xorg-x11-server-Xwayland security update
An update for xorg-x11-server-Xwayland is now available for Red Hat Enterprise Linux 9. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability...
Red Hat Security Advisory: xorg-x11-server security update
An update for xorg-x11-server is now available for Red Hat Enterprise Linux 9.6 Extended Update Support. Red Hat Product Security has rated this update as having a security impact of Important. A Com...
Red Hat Security Advisory: xorg-x11-server security update
An update for xorg-x11-server is now available for Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On. Red...
Red Hat Security Advisory: xorg-x11-server security update
An update for xorg-x11-server is now available for Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On. Red...
Red Hat Security Advisory: xorg-x11-server security update
An update for xorg-x11-server is now available for Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions. Red Hat Product Security has rated this update as having a security impact of Import...
Red Hat Security Advisory: xorg-x11-server security update
An update for xorg-x11-server is now available for Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions. Red Hat Product Security has rated this update as having a security impact of Import...
Red Hat Security Advisory: xorg-x11-server security update
An update for xorg-x11-server is now available for Red Hat Enterprise Linux 7 Extended Lifecycle Support. Red Hat Product Security has rated this update as having a security impact of Important. A Co...
Red Hat Security Advisory: xorg-x11-server security update
An update for xorg-x11-server is now available for Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions and Red Hat Enterprise Linux 8.8 Telecommunications Update Service. Red Hat Product S...
Red Hat Security Advisory: xorg-x11-server-Xwayland security update
An update for xorg-x11-server-Xwayland is now available for Red Hat Enterprise Linux 10.0 Extended Update Support. Red Hat Product Security has rated this update as having a security impact of Import...
Red Hat Security Advisory: xorg-x11-server-Xwayland security update
An update for xorg-x11-server-Xwayland is now available for Red Hat Enterprise Linux 9.6 Extended Update Support. Red Hat Product Security has rated this update as having a security impact of Importa...
Red Hat Security Advisory: xorg-x11-server-Xwayland security update
An update for xorg-x11-server-Xwayland is now available for Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions. Red Hat Product Security has rated this update as having a security impact...
Red Hat Security Advisory: xorg-x11-server-Xwayland security update
An update for xorg-x11-server-Xwayland is now available for Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions and Red Hat Enterprise Linux 8.8 Telecommunications Update Service. Red Hat...
Red Hat Security Advisory: xorg-x11-server-Xwayland security update
An update for xorg-x11-server-Xwayland is now available for Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions. Red Hat Product Security has rated this update as having a security impact...
Red Hat Security Advisory: xorg-x11-server-Xwayland security update
An update for xorg-x11-server-Xwayland is now available for Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add...

> RED HAT SEVERITY ASSESSMENT

THREAT SEVERITY
Important

> OSV (GOOGLE OPEN SOURCE VULNERABILITIES)

xorg-server / xwayland glamor font atlas Heap Buffer Overflow

AFFECTED PACKAGES:
Unknown / Unknown
243 versions affected

> HISTORIQUE DES MODIFICATIONS

Première apparition
08/07/2026 09:16
Source: NVD
📊 ENRICHISSEMENT 01/11/2026 06:59
CWE
Champ modifié: Description CWE
Ancienne valeur:
CWE-122: Heap-based Buffer Overflow - A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the bu...
Nouvelle valeur:
CWE-122: Heap-based Buffer Overflow - The product writes past the end of a buffer that was allocated on the heap.
📊 ENRICHISSEMENT 01/08/2026 06:01
CWE
Champ modifié: Description CWE
Ancienne valeur:
N/A
Nouvelle valeur:
CWE-122: Heap-based Buffer Overflow - A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the bu...
📊 ENRICHISSEMENT 12/07/2026 05:01
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 23:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 22:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 21:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 20:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 19:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 18:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 17:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 16:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 15:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 14:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 13:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 12:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 11:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 10:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 09:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 08:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 07:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 06:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 05:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 04:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 03:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 02:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 01:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
{ "severity_scale": null, "threat_severity": "Important" }
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 00:30
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
N/A
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
📊 ENRICHISSEMENT 09/07/2026 00:30
REDHAT
Champ modifié: Red Hat
Ancienne valeur:
Non
Nouvelle valeur:
Oui
Total des modifications: 28 Dernière mise à jour: 5 days ago

> REFERENCES

https://gitlab.freedesktop.org/xorg/xserver/-/commit/fbf7bac22e2c6bd627fb042742a...
https://www.openwall.com/lists/oss-security/2026/07/08/2
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