Vulnerability details
CVE-2026-49868
RIOT: DHCPv6 client _parse_reply() missing sub-option length check leads to size_t underflow and unbounded OOB heap read
Official description
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.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 9.8Critical | 3.1 | CVEProject cvelistV5 (CNA) (GitHub_M) | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| RIOT-OS | RIOT | < 2026.07 | CVEProject cvelistV5 (CNA) |
References and advisories
4- https://github.com/RIOT-OS/RIOT/security/advisories/GHSA-p3fx-9qcg-jmcf x_refsource_CONFIRM
- https://github.com/RIOT-OS/RIOT/pull/22322 x_refsource_MISC
- https://github.com/RIOT-OS/RIOT/commit/c9830dc5f2a9bf97418de4fc7d7167d00a45df17 x_refsource_MISC
- https://github.com/RIOT-OS/RIOT/releases/tag/2026.07 x_refsource_MISC
Details
- Published
- 2026-10-16
- Last updated
- 2026-10-21
- State
- Published
- Assigner (CNA)
- GitHub_M
- Kolun priority
- 23 · Low
Exploit prediction (EPSS)
SSVC assessment (CISA)
- Automatable
- No
- Exploitation
- None
- Technical impact
- Total
Weaknesses (CWE)
- CWE-125Out-of-bounds Read
- CWE-191Integer Underflow (Wrap or Wraparound)