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TI-2026-75378 Aliases CVE-2026-102692

RIOT nanocoap Block2 overflow allows out-of-bounds memory access

Priority MEDIUM 45CWE-190Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

RIOT before 2026.07 is affected, including the master baseline at commit aeeae69e. The nanocoap CoAP library accepts oversized Block2 option values without enforcing the 20-bit maximum block number, so block offset multiplication overflows on 32-bit targets (CWE-190). A remote client can send a malformed Block2 option that produces an invalid slice range, leading to out-of-bounds memory access, denial of service or memory corruption.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

RIOT is an open-source microcontroller operating system designed for Internet of Things devices and other embedded systems. Prior to 2026.07, nanocoap accepts oversized CoAP Block2 option values without enforcing the 20-bit maximum block number, allowing block offset multiplication to overflow on 32-bit targets. The affected master baseline is commit aeeae69e; the verified fix is later on master and remains unreleased. The oversized value passes from coap_get_blockopt() to coap_block_slicer_init(). A remote CoAP client can send a malformed Block2 option that produces an invalid slice range and can cause out-of-bounds memory access, denial of service, or memory corruption. This vulnerability is fixed in 2026.07.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0035 28th percentileScored 2026-11-07
Fix Fixed RIOT (RIOT-OS): 2026.07

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
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-OSRIOTbefore 2026.072026.07Patch availableCNA
  • RIOT VendorRIOT-OS Affected before 2026.07 Fixed in 2026.07 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:o:riot-os:riot:*:*:*:*:*:*:*:*——RIOT-OS
  • cpe:2.3:o:riot-os:riot:*:*:*:*:*:*:*:* Versions — — ·RIOT-OS

Remediation

The source description says version 2026.07 fixes this flaw, so update RIOT to 2026.07 or later. The verified fix on master is later than the affected baseline and remains unreleased.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

  • Fix · CNA RIOT (RIOT-OS) Fixed in 2026.07

Timeline

  1. 2026-10-16 Threatist record created from CVE-2026-102692
  2. 2026-10-18 CISA SSVC decision points changed

References

Other 4

  • 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-2026-22079 RIOT has an Out-of-Bounds Write in nanoCoAP Handler 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
See all 45 →

Sources

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