---
cve: "CVE-2026-44950"
severity: "CRITICAL"
cvss: 9.5
epss: "0.4%"
vendor: "SUSE"
kev: false
exploited: false
published: "2026-09-10 09:17:02"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-10-26T23:30:59+01:00"
---

# CVE-2026-44950

> 9.5 CRITICAL

## Beschreibung

fs_read_glyphs() in the libXfont2 font-server client (src/fc/fserve.c) copies each glyph's bitmap into a single buffer. Existing checks validates only that the source slice (position, length) lies within the source bitmap buffer. It does not check whether the running destination cursor has exceeded the allocation.

A malicious font server can send overlapping source offsets -- for example 1000 glyphs each referencing {position:0, length:64} with nbytes=64. Each individual source range passes the existing validation, but the cumulative writes total 64000 bytes into a 64-byte destination buffer. This is a heap buffer overflow with attacker-controlled content.

## CNA-Record (Kanon, cvelistV5)

- CNA: **suse**
- State: PUBLISHED
- Stand: 2026-09-10 18:26:50
- CNA-CVSS: **9.0** (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H`)

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **none**
  - Automatable: **no**
  - Technical Impact: **total**

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Schwachstellen-Klasse

- **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 buffer was allocated using a routine such as malloc().

## Angriffsmuster (CAPEC)

- [CAPEC-92 — Forced Integer Overflow](https://capec.mitre.org/data/definitions/92.html) _(Severity: High)_

## BSI-Hinweise (deutsch)

- [X.Org X11 (libXfont2): Mehrere Schwachstellen ermöglichen Privilegieneskalation und Denial of Service](https://wid.cert-bund.de/portal/wid/sicherheitshinweis/WID-SEC-W-2026-2658) — _BSI-Einstufung: mittel_
  Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in X.Org X11 ausnutzen, um seine Privilegien zu erhöhen, und um einen Denial of Service Angriff durchzuführen.

## Referenzen

- <https://bugzilla.suse.com/show_bug.cgi?id=CVE-2026-44950>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-44950/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_