---
cve: "CVE-2026-56099"
severity: "MEDIUM"
cvss: 6.9
epss: "42%"
vendor: "OpenBSD"
kev: false
exploited: false
published: "2026-06-18 20:16:15"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-05T06:02:21+02:00"
---

# CVE-2026-56099

> 6.9 MEDIUM · 🧪 PoC

## Beschreibung

OpenBSD before commit 6a23123 (2026-06-18) contains an out-of-bounds read vulnerability in the mpls_do_error function within sys/netmpls/mpls_input.c that allows remote attackers to disclose kernel stack memory by sending crafted MPLS frames with 16 labels and no Bottom-of-Stack bit set.

## CVSS-Vektor

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

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

## Referenzen

- <https://pop.argus-systems.ai/advisory/adv-040.html>
- <https://github.com/openbsd/src/commit/6a23123ec05f1eb29cfcaae0f3a468b2e1983cfd>
- <https://www.vulncheck.com/advisories/openbsd-mpls-do-error-kernel-stack-memory-disclosure-via-mpls-input>
- <http://seclists.org/fulldisclosure/2026/Jun/17>
- <http://www.openwall.com/lists/oss-security/2026/06/19/3>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-56099) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_