---
cve: "CVE-2026-49868"
severity: "CRITICAL"
cvss: 9.8
epss: "0.4%"
vendor: "RIOT-OS"
kev: false
exploited: false
published: "2026-10-16 17:17:34"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-11-11T02:11:20+01:00"
---

# CVE-2026-49868

> 9.8 CRITICAL · 🧪 PoC

## Beschreibung

RIOT is an open-source microcontroller operating system designed for Internet of Things devices and other embedded systems. Prior to 2026.07, _parse_reply() in sys/net/application_layer/dhcpv6/client.c omits minimum-length validation before passing IA_PD and IA_NA option bodies to sub-option parsers. A malicious or compromised DHCPv6 server can send a REPLY with an option length smaller than the required structure while MODULE_DHCPV6_CLIENT_IA_PD is enabled, causing _parse_ia_pd_option to read past the option body, size_t underflow, and unbounded out-of-bounds heap reads that can crash the device and may expose or corrupt memory. This issue is fixed in version 2026.07.

## CNA-Record (Kanon, cvelistV5)

- CNA: **GitHub_M**
- State: PUBLISHED
- Stand: 2026-10-21 02:29:33
- CNA-CVSS: **9.8** (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
```

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

## Schwachstellen-Klasse

- **CWE-125** — Out-of-bounds Read
  The product reads data past the end, or before the beginning, of the intended buffer.
- **CWE-191** — Integer Underflow (Wrap or Wraparound)
  The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.

## Angriffsmuster (CAPEC)

- [CAPEC-540 — Overread Buffers](https://capec.mitre.org/data/definitions/540.html) _(Severity: High)_

## Patch verfügbar (OSV)

- 50ae2eba8fe3c533539e68f1a64fd34d66c8d14b (Commit)
- c9830dc5f2a9bf97418de4fc7d7167d00a45df17 (Commit)

## Referenzen

- <https://github.com/RIOT-OS/RIOT/security/advisories/GHSA-p3fx-9qcg-jmcf>
- <https://github.com/RIOT-OS/RIOT/pull/22322>
- <https://github.com/RIOT-OS/RIOT/commit/c9830dc5f2a9bf97418de4fc7d7167d00a45df17>
- <https://github.com/RIOT-OS/RIOT/releases/tag/2026.07>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-49868/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_