CVE-2026-102692: CWE-190: Integer Overflow or Wraparound in RIOT-OS RIOT
Description
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.
CVSS v3.1
Score 9.1critical
Affected software
RIOT-OS
RIOT
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
RIOT-OS, an open-source microcontroller operating system, has an integer overflow vulnerability (CWE-190) in its nanocoap component prior to version 2026.07. The vulnerability arises because the nanocoap module accepts oversized CoAP Block2 option values without enforcing the 20-bit maximum block number limit. This allows block offset multiplication to overflow on 32-bit architectures. The malformed Block2 option value propagates from coap_get_blockopt() to coap_block_slicer_init(), resulting in an invalid slice range. This invalid range can cause out-of-bounds memory access, leading to denial of service or memory corruption. The vulnerability is tracked as CVE-2026-102692 and has a CVSS 3.1 score of 9.1 (critical). The fix is implemented in RIOT-OS version 2026.07.
Potential Impact
A remote attacker can exploit this vulnerability by sending a specially crafted CoAP Block2 option that triggers integer overflow in block offset calculations. This can cause out-of-bounds memory access, potentially leading to denial of service or memory corruption on affected 32-bit RIOT-OS devices. The vulnerability does not impact confidentiality but can severely affect integrity and availability.
Mitigation Recommendations
This vulnerability is fixed in RIOT-OS version 2026.07. Users and administrators should upgrade to version 2026.07 or later to remediate this issue. No other mitigation or workaround is indicated by the vendor advisory.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-09-29T16:10:04.076Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ad259172cdf04f6560f7526
Added to database: 10/16/2026, 17:04:23 UTC
Last enriched: 10/16/2026, 17:18:29 UTC
Last updated: 10/16/2026, 21:50:41 UTC
Views: 11
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