---
cve: "CVE-2026-86143"
severity: "MEDIUM"
cvss: 6.9
epss: "3.6%"
vendor: "Generic Security"
kev: false
exploited: false
published: "2026-09-05 05:17:13"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-06T04:25:13+02:00"
---

# CVE-2026-86143

> 6.9 MEDIUM

## Beschreibung

In xmlIO in libxml2 before 2.15.4, an inconsistency in xmlOutputWriteCallback and xmlBufUse causes negative lengths to reach write callbacks, aka a lack of a check for integer overflow before calling writecallback. This has security relevance for many types of uses of that length value within a callback.

## CVSS-Vektor

```
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Lokal | good |
| AC Komplexität | Hoch | good |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Gering | warn |

## Referenzen

- <https://github.com/GNOME/libxml2/commit/90f293ba74d28b1d570920382e707586f68ebf35>
- <https://github.com/GNOME/libxml2/compare/v2.15.3...v2.15.4>
- <https://gitlab.gnome.org/GNOME/libxml2/-/work_items/1111>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-86143) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_