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TI-2026-22079 Aliases CVE-2026-27703

RIOT has an Out-of-Bounds Write in nanoCoAP Handler

Priority HIGH 81CWE-787Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-787 and the CVSS impact.

Summary

RIOT is an open-source microcontroller operating system, designed to match the requirements of Internet of Things (IoT) devices and other embedded devices. In 2026.01 and earlier, the default handler for the well_known_core resource coap_well_known_core_default_handler writes user-provided option data and other data into a fixed size buffer without validating the buffer is large enough to contain the response. This vulnerability allows an attacker to corrupt neighboring stack location, including security-sensitive addresses like the return address, leading to denial of service or arbitrary code execution.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00549 46th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
RIOT-OSRIOTup to 2026.01—No fix listedCNA
  • RIOT VendorRIOT-OS Affected up to 2026.01 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:o:riot-os:riot:*:*:*:*:*:*:*:*up to 2026.01VulnerableRIOT-OS
  • cpe:2.3:o:riot-os:riot:*:*:*:*:*:*:*:* Versions up to 2026.01 Vulnerable ·RIOT-OS

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-27703

References

Exploit 1

  • TI-2024-21112 Buffer overflows in RIOT CVSS 3.1CRITICAL 9.8
  • TI-2023-16843 RIOT-OS vulnerable to Out of Bounds Write in _rbuf_add CVSS 3.1CRITICAL 9.8
  • TI-2023-10319 RIOT-OS vulnerable to Buffer Overflow during IPHC receive CVSS 3.1CRITICAL 9.8
  • TI-2023-16842 RIOT-OS vulnerable to Race Condition in SFR Timeout CVSS 3.1HIGH 7.5
  • TI-2023-16841 RIOT-OS vulnerable to NULL pointer dereference during NHC encoding CVSS 3.1HIGH 7.5
  • TI-2023-10325 RIOT-OS vulnerable to NULL pointer dereference in gnrc_pktbuf_mark CVSS 3.1HIGH 7.5
See all 39 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences